92205c2343
Lock debugging enabled cause huge performance problems for tracing. Having the lock verification happening for every function that is called because mcount calls spin_lock can cripple the system. This patch converts the spin_locks used by ftrace into raw_spin_locks. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2683 lines
59 KiB
C
2683 lines
59 KiB
C
/*
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* ring buffer based function tracer
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* Originally taken from the RT patch by:
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* Arnaldo Carvalho de Melo <acme@redhat.com>
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*
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* Based on code from the latency_tracer, that is:
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 William Lee Irwin III
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*/
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#include <linux/utsrelease.h>
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/debugfs.h>
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#include <linux/pagemap.h>
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#include <linux/hardirq.h>
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#include <linux/linkage.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/module.h>
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#include <linux/percpu.h>
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#include <linux/ctype.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/gfp.h>
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#include <linux/fs.h>
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#include <linux/stacktrace.h>
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#include "trace.h"
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unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
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unsigned long __read_mostly tracing_thresh;
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static int tracing_disabled = 1;
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static long
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ns2usecs(cycle_t nsec)
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{
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nsec += 500;
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do_div(nsec, 1000);
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return nsec;
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}
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cycle_t ftrace_now(int cpu)
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{
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return cpu_clock(cpu);
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}
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static struct trace_array global_trace;
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static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
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static struct trace_array max_tr;
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static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
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static int tracer_enabled = 1;
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static unsigned long trace_nr_entries = 65536UL;
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static struct tracer *trace_types __read_mostly;
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static struct tracer *current_trace __read_mostly;
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static int max_tracer_type_len;
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static DEFINE_MUTEX(trace_types_lock);
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static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
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unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
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void trace_wake_up(void)
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{
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/*
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* The runqueue_is_locked() can fail, but this is the best we
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* have for now:
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*/
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if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
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wake_up(&trace_wait);
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}
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#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
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static int __init set_nr_entries(char *str)
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{
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if (!str)
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return 0;
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trace_nr_entries = simple_strtoul(str, &str, 0);
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return 1;
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}
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__setup("trace_entries=", set_nr_entries);
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unsigned long nsecs_to_usecs(unsigned long nsecs)
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{
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return nsecs / 1000;
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}
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enum trace_type {
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__TRACE_FIRST_TYPE = 0,
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TRACE_FN,
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TRACE_CTX,
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TRACE_WAKE,
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TRACE_STACK,
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TRACE_SPECIAL,
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__TRACE_LAST_TYPE
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};
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enum trace_flag_type {
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TRACE_FLAG_IRQS_OFF = 0x01,
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TRACE_FLAG_NEED_RESCHED = 0x02,
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TRACE_FLAG_HARDIRQ = 0x04,
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TRACE_FLAG_SOFTIRQ = 0x08,
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};
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#define TRACE_ITER_SYM_MASK \
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(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
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/* These must match the bit postions above */
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static const char *trace_options[] = {
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"print-parent",
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"sym-offset",
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"sym-addr",
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"verbose",
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"raw",
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"hex",
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"bin",
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"block",
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"stacktrace",
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"sched-tree",
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NULL
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};
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static raw_spinlock_t ftrace_max_lock =
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(raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
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/*
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* Copy the new maximum trace into the separate maximum-trace
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* structure. (this way the maximum trace is permanently saved,
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* for later retrieval via /debugfs/tracing/latency_trace)
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*/
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static void
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__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
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{
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struct trace_array_cpu *data = tr->data[cpu];
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max_tr.cpu = cpu;
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max_tr.time_start = data->preempt_timestamp;
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data = max_tr.data[cpu];
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data->saved_latency = tracing_max_latency;
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memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
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data->pid = tsk->pid;
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data->uid = tsk->uid;
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data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
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data->policy = tsk->policy;
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data->rt_priority = tsk->rt_priority;
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/* record this tasks comm */
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tracing_record_cmdline(current);
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}
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void check_pages(struct trace_array_cpu *data)
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{
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struct page *page, *tmp;
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BUG_ON(data->trace_pages.next->prev != &data->trace_pages);
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BUG_ON(data->trace_pages.prev->next != &data->trace_pages);
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list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
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BUG_ON(page->lru.next->prev != &page->lru);
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BUG_ON(page->lru.prev->next != &page->lru);
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}
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}
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void *head_page(struct trace_array_cpu *data)
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{
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struct page *page;
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check_pages(data);
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if (list_empty(&data->trace_pages))
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return NULL;
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page = list_entry(data->trace_pages.next, struct page, lru);
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BUG_ON(&page->lru == &data->trace_pages);
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return page_address(page);
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}
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static int
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trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
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{
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int len = (PAGE_SIZE - 1) - s->len;
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va_list ap;
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int ret;
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if (!len)
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return 0;
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va_start(ap, fmt);
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ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
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va_end(ap);
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/* If we can't write it all, don't bother writing anything */
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if (ret > len)
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return 0;
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s->len += ret;
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return len;
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}
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static int
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trace_seq_puts(struct trace_seq *s, const char *str)
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{
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int len = strlen(str);
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if (len > ((PAGE_SIZE - 1) - s->len))
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return 0;
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memcpy(s->buffer + s->len, str, len);
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s->len += len;
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return len;
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}
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static int
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trace_seq_putc(struct trace_seq *s, unsigned char c)
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{
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if (s->len >= (PAGE_SIZE - 1))
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return 0;
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s->buffer[s->len++] = c;
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return 1;
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}
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static int
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trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
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{
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if (len > ((PAGE_SIZE - 1) - s->len))
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return 0;
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memcpy(s->buffer + s->len, mem, len);
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s->len += len;
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return len;
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}
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#define HEX_CHARS 17
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static int
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trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
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{
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unsigned char hex[HEX_CHARS];
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unsigned char *data;
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unsigned char byte;
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int i, j;
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BUG_ON(len >= HEX_CHARS);
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data = mem;
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#ifdef __BIG_ENDIAN
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for (i = 0, j = 0; i < len; i++) {
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#else
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for (i = len-1, j = 0; i >= 0; i--) {
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#endif
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byte = data[i];
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hex[j] = byte & 0x0f;
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if (hex[j] >= 10)
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hex[j] += 'a' - 10;
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else
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hex[j] += '0';
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j++;
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hex[j] = byte >> 4;
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if (hex[j] >= 10)
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hex[j] += 'a' - 10;
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else
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hex[j] += '0';
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j++;
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}
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hex[j] = ' ';
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j++;
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return trace_seq_putmem(s, hex, j);
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}
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static void
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trace_seq_reset(struct trace_seq *s)
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{
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s->len = 0;
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}
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static void
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trace_print_seq(struct seq_file *m, struct trace_seq *s)
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{
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int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
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s->buffer[len] = 0;
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seq_puts(m, s->buffer);
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trace_seq_reset(s);
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}
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static void
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flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
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{
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struct list_head flip_pages;
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INIT_LIST_HEAD(&flip_pages);
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memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
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sizeof(struct trace_array_cpu) -
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offsetof(struct trace_array_cpu, trace_head_idx));
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check_pages(tr1);
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check_pages(tr2);
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list_splice_init(&tr1->trace_pages, &flip_pages);
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list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
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list_splice_init(&flip_pages, &tr2->trace_pages);
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BUG_ON(!list_empty(&flip_pages));
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check_pages(tr1);
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check_pages(tr2);
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}
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void
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update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
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{
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struct trace_array_cpu *data;
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int i;
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WARN_ON_ONCE(!irqs_disabled());
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__raw_spin_lock(&ftrace_max_lock);
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/* clear out all the previous traces */
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for_each_possible_cpu(i) {
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data = tr->data[i];
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flip_trace(max_tr.data[i], data);
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tracing_reset(data);
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}
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__update_max_tr(tr, tsk, cpu);
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__raw_spin_unlock(&ftrace_max_lock);
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}
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/**
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* update_max_tr_single - only copy one trace over, and reset the rest
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* @tr - tracer
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* @tsk - task with the latency
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* @cpu - the cpu of the buffer to copy.
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*/
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void
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update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
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{
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struct trace_array_cpu *data = tr->data[cpu];
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int i;
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WARN_ON_ONCE(!irqs_disabled());
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__raw_spin_lock(&ftrace_max_lock);
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for_each_possible_cpu(i)
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tracing_reset(max_tr.data[i]);
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flip_trace(max_tr.data[cpu], data);
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tracing_reset(data);
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__update_max_tr(tr, tsk, cpu);
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__raw_spin_unlock(&ftrace_max_lock);
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}
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|
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int register_tracer(struct tracer *type)
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{
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struct tracer *t;
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int len;
|
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int ret = 0;
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|
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if (!type->name) {
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pr_info("Tracer must have a name\n");
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return -1;
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}
|
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|
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mutex_lock(&trace_types_lock);
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for (t = trace_types; t; t = t->next) {
|
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if (strcmp(type->name, t->name) == 0) {
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/* already found */
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pr_info("Trace %s already registered\n",
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type->name);
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ret = -1;
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goto out;
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}
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}
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|
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#ifdef CONFIG_FTRACE_STARTUP_TEST
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if (type->selftest) {
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struct tracer *saved_tracer = current_trace;
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struct trace_array_cpu *data;
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struct trace_array *tr = &global_trace;
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int saved_ctrl = tr->ctrl;
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int i;
|
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/*
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* Run a selftest on this tracer.
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* Here we reset the trace buffer, and set the current
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* tracer to be this tracer. The tracer can then run some
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* internal tracing to verify that everything is in order.
|
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* If we fail, we do not register this tracer.
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*/
|
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for_each_possible_cpu(i) {
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data = tr->data[i];
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if (!head_page(data))
|
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continue;
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tracing_reset(data);
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}
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current_trace = type;
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tr->ctrl = 0;
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/* the test is responsible for initializing and enabling */
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pr_info("Testing tracer %s: ", type->name);
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ret = type->selftest(type, tr);
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/* the test is responsible for resetting too */
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current_trace = saved_tracer;
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tr->ctrl = saved_ctrl;
|
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if (ret) {
|
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printk(KERN_CONT "FAILED!\n");
|
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goto out;
|
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}
|
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/* Only reset on passing, to avoid touching corrupted buffers */
|
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for_each_possible_cpu(i) {
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data = tr->data[i];
|
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if (!head_page(data))
|
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continue;
|
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tracing_reset(data);
|
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}
|
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printk(KERN_CONT "PASSED\n");
|
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}
|
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#endif
|
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|
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type->next = trace_types;
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trace_types = type;
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len = strlen(type->name);
|
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if (len > max_tracer_type_len)
|
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max_tracer_type_len = len;
|
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|
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out:
|
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mutex_unlock(&trace_types_lock);
|
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|
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return ret;
|
|
}
|
|
|
|
void unregister_tracer(struct tracer *type)
|
|
{
|
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struct tracer **t;
|
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int len;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (t = &trace_types; *t; t = &(*t)->next) {
|
|
if (*t == type)
|
|
goto found;
|
|
}
|
|
pr_info("Trace %s not registered\n", type->name);
|
|
goto out;
|
|
|
|
found:
|
|
*t = (*t)->next;
|
|
if (strlen(type->name) != max_tracer_type_len)
|
|
goto out;
|
|
|
|
max_tracer_type_len = 0;
|
|
for (t = &trace_types; *t; t = &(*t)->next) {
|
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len = strlen((*t)->name);
|
|
if (len > max_tracer_type_len)
|
|
max_tracer_type_len = len;
|
|
}
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
void tracing_reset(struct trace_array_cpu *data)
|
|
{
|
|
data->trace_idx = 0;
|
|
data->trace_head = data->trace_tail = head_page(data);
|
|
data->trace_head_idx = 0;
|
|
data->trace_tail_idx = 0;
|
|
}
|
|
|
|
#define SAVED_CMDLINES 128
|
|
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
|
|
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
|
|
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
|
|
static int cmdline_idx;
|
|
static DEFINE_SPINLOCK(trace_cmdline_lock);
|
|
atomic_t trace_record_cmdline_disabled;
|
|
|
|
static void trace_init_cmdlines(void)
|
|
{
|
|
memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
|
|
memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
|
|
cmdline_idx = 0;
|
|
}
|
|
|
|
void trace_stop_cmdline_recording(void);
|
|
|
|
static void trace_save_cmdline(struct task_struct *tsk)
|
|
{
|
|
unsigned map;
|
|
unsigned idx;
|
|
|
|
if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
|
|
return;
|
|
|
|
/*
|
|
* It's not the end of the world if we don't get
|
|
* the lock, but we also don't want to spin
|
|
* nor do we want to disable interrupts,
|
|
* so if we miss here, then better luck next time.
|
|
*/
|
|
if (!spin_trylock(&trace_cmdline_lock))
|
|
return;
|
|
|
|
idx = map_pid_to_cmdline[tsk->pid];
|
|
if (idx >= SAVED_CMDLINES) {
|
|
idx = (cmdline_idx + 1) % SAVED_CMDLINES;
|
|
|
|
map = map_cmdline_to_pid[idx];
|
|
if (map <= PID_MAX_DEFAULT)
|
|
map_pid_to_cmdline[map] = (unsigned)-1;
|
|
|
|
map_pid_to_cmdline[tsk->pid] = idx;
|
|
|
|
cmdline_idx = idx;
|
|
}
|
|
|
|
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
|
|
|
|
spin_unlock(&trace_cmdline_lock);
|
|
}
|
|
|
|
static char *trace_find_cmdline(int pid)
|
|
{
|
|
char *cmdline = "<...>";
|
|
unsigned map;
|
|
|
|
if (!pid)
|
|
return "<idle>";
|
|
|
|
if (pid > PID_MAX_DEFAULT)
|
|
goto out;
|
|
|
|
map = map_pid_to_cmdline[pid];
|
|
if (map >= SAVED_CMDLINES)
|
|
goto out;
|
|
|
|
cmdline = saved_cmdlines[map];
|
|
|
|
out:
|
|
return cmdline;
|
|
}
|
|
|
|
void tracing_record_cmdline(struct task_struct *tsk)
|
|
{
|
|
if (atomic_read(&trace_record_cmdline_disabled))
|
|
return;
|
|
|
|
trace_save_cmdline(tsk);
|
|
}
|
|
|
|
static inline struct list_head *
|
|
trace_next_list(struct trace_array_cpu *data, struct list_head *next)
|
|
{
|
|
/*
|
|
* Roundrobin - but skip the head (which is not a real page):
|
|
*/
|
|
next = next->next;
|
|
if (unlikely(next == &data->trace_pages))
|
|
next = next->next;
|
|
BUG_ON(next == &data->trace_pages);
|
|
|
|
return next;
|
|
}
|
|
|
|
static inline void *
|
|
trace_next_page(struct trace_array_cpu *data, void *addr)
|
|
{
|
|
struct list_head *next;
|
|
struct page *page;
|
|
|
|
page = virt_to_page(addr);
|
|
|
|
next = trace_next_list(data, &page->lru);
|
|
page = list_entry(next, struct page, lru);
|
|
|
|
return page_address(page);
|
|
}
|
|
|
|
static inline struct trace_entry *
|
|
tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
|
|
{
|
|
unsigned long idx, idx_next;
|
|
struct trace_entry *entry;
|
|
|
|
data->trace_idx++;
|
|
idx = data->trace_head_idx;
|
|
idx_next = idx + 1;
|
|
|
|
BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
|
|
|
|
entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
|
|
|
|
if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
|
|
data->trace_head = trace_next_page(data, data->trace_head);
|
|
idx_next = 0;
|
|
}
|
|
|
|
if (data->trace_head == data->trace_tail &&
|
|
idx_next == data->trace_tail_idx) {
|
|
/* overrun */
|
|
data->trace_tail_idx++;
|
|
if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
|
|
data->trace_tail =
|
|
trace_next_page(data, data->trace_tail);
|
|
data->trace_tail_idx = 0;
|
|
}
|
|
}
|
|
|
|
data->trace_head_idx = idx_next;
|
|
|
|
return entry;
|
|
}
|
|
|
|
static inline void
|
|
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
unsigned long pc;
|
|
|
|
pc = preempt_count();
|
|
|
|
entry->preempt_count = pc & 0xff;
|
|
entry->pid = tsk->pid;
|
|
entry->t = ftrace_now(raw_smp_processor_id());
|
|
entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
|
|
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
|
|
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
|
|
(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
|
|
}
|
|
|
|
void
|
|
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags)
|
|
{
|
|
struct trace_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
raw_local_irq_save(irq_flags);
|
|
__raw_spin_lock(&data->lock);
|
|
entry = tracing_get_trace_entry(tr, data);
|
|
tracing_generic_entry_update(entry, flags);
|
|
entry->type = TRACE_FN;
|
|
entry->fn.ip = ip;
|
|
entry->fn.parent_ip = parent_ip;
|
|
__raw_spin_unlock(&data->lock);
|
|
raw_local_irq_restore(irq_flags);
|
|
}
|
|
|
|
void
|
|
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags)
|
|
{
|
|
if (likely(!atomic_read(&data->disabled)))
|
|
trace_function(tr, data, ip, parent_ip, flags);
|
|
}
|
|
|
|
void
|
|
__trace_special(void *__tr, void *__data,
|
|
unsigned long arg1, unsigned long arg2, unsigned long arg3)
|
|
{
|
|
struct trace_array_cpu *data = __data;
|
|
struct trace_array *tr = __tr;
|
|
struct trace_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
raw_local_irq_save(irq_flags);
|
|
__raw_spin_lock(&data->lock);
|
|
entry = tracing_get_trace_entry(tr, data);
|
|
tracing_generic_entry_update(entry, 0);
|
|
entry->type = TRACE_SPECIAL;
|
|
entry->special.arg1 = arg1;
|
|
entry->special.arg2 = arg2;
|
|
entry->special.arg3 = arg3;
|
|
__raw_spin_unlock(&data->lock);
|
|
raw_local_irq_restore(irq_flags);
|
|
|
|
trace_wake_up();
|
|
}
|
|
|
|
void __trace_stack(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
unsigned long flags,
|
|
int skip)
|
|
{
|
|
struct trace_entry *entry;
|
|
struct stack_trace trace;
|
|
|
|
if (!(trace_flags & TRACE_ITER_STACKTRACE))
|
|
return;
|
|
|
|
entry = tracing_get_trace_entry(tr, data);
|
|
tracing_generic_entry_update(entry, flags);
|
|
entry->type = TRACE_STACK;
|
|
|
|
memset(&entry->stack, 0, sizeof(entry->stack));
|
|
|
|
trace.nr_entries = 0;
|
|
trace.max_entries = FTRACE_STACK_ENTRIES;
|
|
trace.skip = skip;
|
|
trace.entries = entry->stack.caller;
|
|
|
|
save_stack_trace(&trace);
|
|
}
|
|
|
|
void
|
|
tracing_sched_switch_trace(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct task_struct *prev,
|
|
struct task_struct *next,
|
|
unsigned long flags)
|
|
{
|
|
struct trace_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
raw_local_irq_save(irq_flags);
|
|
__raw_spin_lock(&data->lock);
|
|
entry = tracing_get_trace_entry(tr, data);
|
|
tracing_generic_entry_update(entry, flags);
|
|
entry->type = TRACE_CTX;
|
|
entry->ctx.prev_pid = prev->pid;
|
|
entry->ctx.prev_prio = prev->prio;
|
|
entry->ctx.prev_state = prev->state;
|
|
entry->ctx.next_pid = next->pid;
|
|
entry->ctx.next_prio = next->prio;
|
|
entry->ctx.next_state = next->state;
|
|
__trace_stack(tr, data, flags, 4);
|
|
__raw_spin_unlock(&data->lock);
|
|
raw_local_irq_restore(irq_flags);
|
|
}
|
|
|
|
void
|
|
tracing_sched_wakeup_trace(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct task_struct *wakee,
|
|
struct task_struct *curr,
|
|
unsigned long flags)
|
|
{
|
|
struct trace_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
raw_local_irq_save(irq_flags);
|
|
__raw_spin_lock(&data->lock);
|
|
entry = tracing_get_trace_entry(tr, data);
|
|
tracing_generic_entry_update(entry, flags);
|
|
entry->type = TRACE_WAKE;
|
|
entry->ctx.prev_pid = curr->pid;
|
|
entry->ctx.prev_prio = curr->prio;
|
|
entry->ctx.prev_state = curr->state;
|
|
entry->ctx.next_pid = wakee->pid;
|
|
entry->ctx.next_prio = wakee->prio;
|
|
entry->ctx.next_state = wakee->state;
|
|
__trace_stack(tr, data, flags, 5);
|
|
__raw_spin_unlock(&data->lock);
|
|
raw_local_irq_restore(irq_flags);
|
|
|
|
trace_wake_up();
|
|
}
|
|
|
|
#ifdef CONFIG_FTRACE
|
|
static void
|
|
function_trace_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
|
|
if (unlikely(!tracer_enabled))
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1))
|
|
trace_function(tr, data, ip, parent_ip, flags);
|
|
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static struct ftrace_ops trace_ops __read_mostly =
|
|
{
|
|
.func = function_trace_call,
|
|
};
|
|
|
|
void tracing_start_function_trace(void)
|
|
{
|
|
register_ftrace_function(&trace_ops);
|
|
}
|
|
|
|
void tracing_stop_function_trace(void)
|
|
{
|
|
unregister_ftrace_function(&trace_ops);
|
|
}
|
|
#endif
|
|
|
|
enum trace_file_type {
|
|
TRACE_FILE_LAT_FMT = 1,
|
|
};
|
|
|
|
static struct trace_entry *
|
|
trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
|
|
struct trace_iterator *iter, int cpu)
|
|
{
|
|
struct page *page;
|
|
struct trace_entry *array;
|
|
|
|
if (iter->next_idx[cpu] >= tr->entries ||
|
|
iter->next_idx[cpu] >= data->trace_idx ||
|
|
(data->trace_head == data->trace_tail &&
|
|
data->trace_head_idx == data->trace_tail_idx))
|
|
return NULL;
|
|
|
|
if (!iter->next_page[cpu]) {
|
|
/* Initialize the iterator for this cpu trace buffer */
|
|
WARN_ON(!data->trace_tail);
|
|
page = virt_to_page(data->trace_tail);
|
|
iter->next_page[cpu] = &page->lru;
|
|
iter->next_page_idx[cpu] = data->trace_tail_idx;
|
|
}
|
|
|
|
page = list_entry(iter->next_page[cpu], struct page, lru);
|
|
BUG_ON(&data->trace_pages == &page->lru);
|
|
|
|
array = page_address(page);
|
|
|
|
WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
|
|
return &array[iter->next_page_idx[cpu]];
|
|
}
|
|
|
|
static struct trace_entry *
|
|
find_next_entry(struct trace_iterator *iter, int *ent_cpu)
|
|
{
|
|
struct trace_array *tr = iter->tr;
|
|
struct trace_entry *ent, *next = NULL;
|
|
int next_cpu = -1;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
if (!head_page(tr->data[cpu]))
|
|
continue;
|
|
ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
|
|
/*
|
|
* Pick the entry with the smallest timestamp:
|
|
*/
|
|
if (ent && (!next || ent->t < next->t)) {
|
|
next = ent;
|
|
next_cpu = cpu;
|
|
}
|
|
}
|
|
|
|
if (ent_cpu)
|
|
*ent_cpu = next_cpu;
|
|
|
|
return next;
|
|
}
|
|
|
|
static void trace_iterator_increment(struct trace_iterator *iter)
|
|
{
|
|
iter->idx++;
|
|
iter->next_idx[iter->cpu]++;
|
|
iter->next_page_idx[iter->cpu]++;
|
|
|
|
if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
|
|
struct trace_array_cpu *data = iter->tr->data[iter->cpu];
|
|
|
|
iter->next_page_idx[iter->cpu] = 0;
|
|
iter->next_page[iter->cpu] =
|
|
trace_next_list(data, iter->next_page[iter->cpu]);
|
|
}
|
|
}
|
|
|
|
static void trace_consume(struct trace_iterator *iter)
|
|
{
|
|
struct trace_array_cpu *data = iter->tr->data[iter->cpu];
|
|
|
|
data->trace_tail_idx++;
|
|
if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
|
|
data->trace_tail = trace_next_page(data, data->trace_tail);
|
|
data->trace_tail_idx = 0;
|
|
}
|
|
|
|
/* Check if we empty it, then reset the index */
|
|
if (data->trace_head == data->trace_tail &&
|
|
data->trace_head_idx == data->trace_tail_idx)
|
|
data->trace_idx = 0;
|
|
}
|
|
|
|
static void *find_next_entry_inc(struct trace_iterator *iter)
|
|
{
|
|
struct trace_entry *next;
|
|
int next_cpu = -1;
|
|
|
|
next = find_next_entry(iter, &next_cpu);
|
|
|
|
iter->prev_ent = iter->ent;
|
|
iter->prev_cpu = iter->cpu;
|
|
|
|
iter->ent = next;
|
|
iter->cpu = next_cpu;
|
|
|
|
if (next)
|
|
trace_iterator_increment(iter);
|
|
|
|
return next ? iter : NULL;
|
|
}
|
|
|
|
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
void *last_ent = iter->ent;
|
|
int i = (int)*pos;
|
|
void *ent;
|
|
|
|
(*pos)++;
|
|
|
|
/* can't go backwards */
|
|
if (iter->idx > i)
|
|
return NULL;
|
|
|
|
if (iter->idx < 0)
|
|
ent = find_next_entry_inc(iter);
|
|
else
|
|
ent = iter;
|
|
|
|
while (ent && iter->idx < i)
|
|
ent = find_next_entry_inc(iter);
|
|
|
|
iter->pos = *pos;
|
|
|
|
if (last_ent && !ent)
|
|
seq_puts(m, "\n\nvim:ft=help\n");
|
|
|
|
return ent;
|
|
}
|
|
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
void *p = NULL;
|
|
loff_t l = 0;
|
|
int i;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (!current_trace || current_trace != iter->trace)
|
|
return NULL;
|
|
|
|
atomic_inc(&trace_record_cmdline_disabled);
|
|
|
|
/* let the tracer grab locks here if needed */
|
|
if (current_trace->start)
|
|
current_trace->start(iter);
|
|
|
|
if (*pos != iter->pos) {
|
|
iter->ent = NULL;
|
|
iter->cpu = 0;
|
|
iter->idx = -1;
|
|
iter->prev_ent = NULL;
|
|
iter->prev_cpu = -1;
|
|
|
|
for_each_possible_cpu(i) {
|
|
iter->next_idx[i] = 0;
|
|
iter->next_page[i] = NULL;
|
|
}
|
|
|
|
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
|
|
;
|
|
|
|
} else {
|
|
l = *pos - 1;
|
|
p = s_next(m, p, &l);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
static void s_stop(struct seq_file *m, void *p)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
|
|
atomic_dec(&trace_record_cmdline_disabled);
|
|
|
|
/* let the tracer release locks here if needed */
|
|
if (current_trace && current_trace == iter->trace && iter->trace->stop)
|
|
iter->trace->stop(iter);
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
static int
|
|
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
|
|
{
|
|
#ifdef CONFIG_KALLSYMS
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
kallsyms_lookup(address, NULL, NULL, NULL, str);
|
|
|
|
return trace_seq_printf(s, fmt, str);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
|
|
unsigned long address)
|
|
{
|
|
#ifdef CONFIG_KALLSYMS
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
sprint_symbol(str, address);
|
|
return trace_seq_printf(s, fmt, str);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
#ifndef CONFIG_64BIT
|
|
# define IP_FMT "%08lx"
|
|
#else
|
|
# define IP_FMT "%016lx"
|
|
#endif
|
|
|
|
static int
|
|
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
|
|
{
|
|
int ret;
|
|
|
|
if (!ip)
|
|
return trace_seq_printf(s, "0");
|
|
|
|
if (sym_flags & TRACE_ITER_SYM_OFFSET)
|
|
ret = seq_print_sym_offset(s, "%s", ip);
|
|
else
|
|
ret = seq_print_sym_short(s, "%s", ip);
|
|
|
|
if (!ret)
|
|
return 0;
|
|
|
|
if (sym_flags & TRACE_ITER_SYM_ADDR)
|
|
ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
|
|
return ret;
|
|
}
|
|
|
|
static void print_lat_help_header(struct seq_file *m)
|
|
{
|
|
seq_puts(m, "# _------=> CPU# \n");
|
|
seq_puts(m, "# / _-----=> irqs-off \n");
|
|
seq_puts(m, "# | / _----=> need-resched \n");
|
|
seq_puts(m, "# || / _---=> hardirq/softirq \n");
|
|
seq_puts(m, "# ||| / _--=> preempt-depth \n");
|
|
seq_puts(m, "# |||| / \n");
|
|
seq_puts(m, "# ||||| delay \n");
|
|
seq_puts(m, "# cmd pid ||||| time | caller \n");
|
|
seq_puts(m, "# \\ / ||||| \\ | / \n");
|
|
}
|
|
|
|
static void print_func_help_header(struct seq_file *m)
|
|
{
|
|
seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
|
|
seq_puts(m, "# | | | | |\n");
|
|
}
|
|
|
|
|
|
static void
|
|
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
|
|
{
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_array *tr = iter->tr;
|
|
struct trace_array_cpu *data = tr->data[tr->cpu];
|
|
struct tracer *type = current_trace;
|
|
unsigned long total = 0;
|
|
unsigned long entries = 0;
|
|
int cpu;
|
|
const char *name = "preemption";
|
|
|
|
if (type)
|
|
name = type->name;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
if (head_page(tr->data[cpu])) {
|
|
total += tr->data[cpu]->trace_idx;
|
|
if (tr->data[cpu]->trace_idx > tr->entries)
|
|
entries += tr->entries;
|
|
else
|
|
entries += tr->data[cpu]->trace_idx;
|
|
}
|
|
}
|
|
|
|
seq_printf(m, "%s latency trace v1.1.5 on %s\n",
|
|
name, UTS_RELEASE);
|
|
seq_puts(m, "-----------------------------------"
|
|
"---------------------------------\n");
|
|
seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
|
|
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
|
|
nsecs_to_usecs(data->saved_latency),
|
|
entries,
|
|
total,
|
|
tr->cpu,
|
|
#if defined(CONFIG_PREEMPT_NONE)
|
|
"server",
|
|
#elif defined(CONFIG_PREEMPT_VOLUNTARY)
|
|
"desktop",
|
|
#elif defined(CONFIG_PREEMPT_DESKTOP)
|
|
"preempt",
|
|
#else
|
|
"unknown",
|
|
#endif
|
|
/* These are reserved for later use */
|
|
0, 0, 0, 0);
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(m, " #P:%d)\n", num_online_cpus());
|
|
#else
|
|
seq_puts(m, ")\n");
|
|
#endif
|
|
seq_puts(m, " -----------------\n");
|
|
seq_printf(m, " | task: %.16s-%d "
|
|
"(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
|
|
data->comm, data->pid, data->uid, data->nice,
|
|
data->policy, data->rt_priority);
|
|
seq_puts(m, " -----------------\n");
|
|
|
|
if (data->critical_start) {
|
|
seq_puts(m, " => started at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n => ended at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n");
|
|
}
|
|
|
|
seq_puts(m, "\n");
|
|
}
|
|
|
|
static void
|
|
lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
|
|
{
|
|
int hardirq, softirq;
|
|
char *comm;
|
|
|
|
comm = trace_find_cmdline(entry->pid);
|
|
|
|
trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
|
|
trace_seq_printf(s, "%d", cpu);
|
|
trace_seq_printf(s, "%c%c",
|
|
(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
|
|
((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
|
|
|
|
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
|
|
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
|
|
if (hardirq && softirq)
|
|
trace_seq_putc(s, 'H');
|
|
else {
|
|
if (hardirq)
|
|
trace_seq_putc(s, 'h');
|
|
else {
|
|
if (softirq)
|
|
trace_seq_putc(s, 's');
|
|
else
|
|
trace_seq_putc(s, '.');
|
|
}
|
|
}
|
|
|
|
if (entry->preempt_count)
|
|
trace_seq_printf(s, "%x", entry->preempt_count);
|
|
else
|
|
trace_seq_puts(s, ".");
|
|
}
|
|
|
|
unsigned long preempt_mark_thresh = 100;
|
|
|
|
static void
|
|
lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
|
|
unsigned long rel_usecs)
|
|
{
|
|
trace_seq_printf(s, " %4lldus", abs_usecs);
|
|
if (rel_usecs > preempt_mark_thresh)
|
|
trace_seq_puts(s, "!: ");
|
|
else if (rel_usecs > 1)
|
|
trace_seq_puts(s, "+: ");
|
|
else
|
|
trace_seq_puts(s, " : ");
|
|
}
|
|
|
|
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
|
|
|
|
static int
|
|
print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_entry *next_entry = find_next_entry(iter, NULL);
|
|
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
|
|
struct trace_entry *entry = iter->ent;
|
|
unsigned long abs_usecs;
|
|
unsigned long rel_usecs;
|
|
char *comm;
|
|
int S, T;
|
|
int i;
|
|
|
|
if (!next_entry)
|
|
next_entry = entry;
|
|
rel_usecs = ns2usecs(next_entry->t - entry->t);
|
|
abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
|
|
|
|
if (verbose) {
|
|
comm = trace_find_cmdline(entry->pid);
|
|
trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
|
|
" %ld.%03ldms (+%ld.%03ldms): ",
|
|
comm,
|
|
entry->pid, cpu, entry->flags,
|
|
entry->preempt_count, trace_idx,
|
|
ns2usecs(entry->t),
|
|
abs_usecs/1000,
|
|
abs_usecs % 1000, rel_usecs/1000,
|
|
rel_usecs % 1000);
|
|
} else {
|
|
lat_print_generic(s, entry, cpu);
|
|
lat_print_timestamp(s, abs_usecs, rel_usecs);
|
|
}
|
|
switch (entry->type) {
|
|
case TRACE_FN:
|
|
seq_print_ip_sym(s, entry->fn.ip, sym_flags);
|
|
trace_seq_puts(s, " (");
|
|
seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
|
|
trace_seq_puts(s, ")\n");
|
|
break;
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE:
|
|
S = entry->ctx.prev_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.prev_state] : 'X';
|
|
T = entry->ctx.next_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.next_state] : 'X';
|
|
|
|
comm = trace_find_cmdline(entry->ctx.next_pid);
|
|
trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
|
|
entry->ctx.prev_pid,
|
|
entry->ctx.prev_prio,
|
|
S, entry->type == TRACE_CTX ? "==>" : " +",
|
|
entry->ctx.next_pid,
|
|
entry->ctx.next_prio,
|
|
T, comm);
|
|
break;
|
|
case TRACE_SPECIAL:
|
|
trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
entry->special.arg1,
|
|
entry->special.arg2,
|
|
entry->special.arg3);
|
|
break;
|
|
case TRACE_STACK:
|
|
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
|
|
if (i)
|
|
trace_seq_puts(s, " <= ");
|
|
seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
|
|
}
|
|
trace_seq_puts(s, "\n");
|
|
break;
|
|
default:
|
|
trace_seq_printf(s, "Unknown type %d\n", entry->type);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int print_trace_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_entry *entry;
|
|
unsigned long usec_rem;
|
|
unsigned long long t;
|
|
unsigned long secs;
|
|
char *comm;
|
|
int ret;
|
|
int S, T;
|
|
int i;
|
|
|
|
entry = iter->ent;
|
|
|
|
comm = trace_find_cmdline(iter->ent->pid);
|
|
|
|
t = ns2usecs(entry->t);
|
|
usec_rem = do_div(t, 1000000ULL);
|
|
secs = (unsigned long)t;
|
|
|
|
ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
|
|
if (!ret)
|
|
return 0;
|
|
ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
|
|
if (!ret)
|
|
return 0;
|
|
ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN:
|
|
ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
|
|
if (!ret)
|
|
return 0;
|
|
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
|
|
entry->fn.parent_ip) {
|
|
ret = trace_seq_printf(s, " <-");
|
|
if (!ret)
|
|
return 0;
|
|
ret = seq_print_ip_sym(s, entry->fn.parent_ip,
|
|
sym_flags);
|
|
if (!ret)
|
|
return 0;
|
|
}
|
|
ret = trace_seq_printf(s, "\n");
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE:
|
|
S = entry->ctx.prev_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.prev_state] : 'X';
|
|
T = entry->ctx.next_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.next_state] : 'X';
|
|
ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
|
|
entry->ctx.prev_pid,
|
|
entry->ctx.prev_prio,
|
|
S,
|
|
entry->type == TRACE_CTX ? "==>" : " +",
|
|
entry->ctx.next_pid,
|
|
entry->ctx.next_prio,
|
|
T);
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
case TRACE_SPECIAL:
|
|
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
entry->special.arg1,
|
|
entry->special.arg2,
|
|
entry->special.arg3);
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
case TRACE_STACK:
|
|
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
|
|
if (i) {
|
|
ret = trace_seq_puts(s, " <= ");
|
|
if (!ret)
|
|
return 0;
|
|
}
|
|
ret = seq_print_ip_sym(s, entry->stack.caller[i],
|
|
sym_flags);
|
|
if (!ret)
|
|
return 0;
|
|
}
|
|
ret = trace_seq_puts(s, "\n");
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int print_raw_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
int ret;
|
|
int S, T;
|
|
|
|
entry = iter->ent;
|
|
|
|
ret = trace_seq_printf(s, "%d %d %llu ",
|
|
entry->pid, iter->cpu, entry->t);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN:
|
|
ret = trace_seq_printf(s, "%x %x\n",
|
|
entry->fn.ip, entry->fn.parent_ip);
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE:
|
|
S = entry->ctx.prev_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.prev_state] : 'X';
|
|
T = entry->ctx.next_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.next_state] : 'X';
|
|
if (entry->type == TRACE_WAKE)
|
|
S = '+';
|
|
ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
|
|
entry->ctx.prev_pid,
|
|
entry->ctx.prev_prio,
|
|
S,
|
|
entry->ctx.next_pid,
|
|
entry->ctx.next_prio,
|
|
T);
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
case TRACE_SPECIAL:
|
|
case TRACE_STACK:
|
|
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
entry->special.arg1,
|
|
entry->special.arg2,
|
|
entry->special.arg3);
|
|
if (!ret)
|
|
return 0;
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
#define SEQ_PUT_FIELD_RET(s, x) \
|
|
do { \
|
|
if (!trace_seq_putmem(s, &(x), sizeof(x))) \
|
|
return 0; \
|
|
} while (0)
|
|
|
|
#define SEQ_PUT_HEX_FIELD_RET(s, x) \
|
|
do { \
|
|
if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
|
|
return 0; \
|
|
} while (0)
|
|
|
|
static int print_hex_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned char newline = '\n';
|
|
struct trace_entry *entry;
|
|
int S, T;
|
|
|
|
entry = iter->ent;
|
|
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->t);
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN:
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
|
|
break;
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE:
|
|
S = entry->ctx.prev_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.prev_state] : 'X';
|
|
T = entry->ctx.next_state < sizeof(state_to_char) ?
|
|
state_to_char[entry->ctx.next_state] : 'X';
|
|
if (entry->type == TRACE_WAKE)
|
|
S = '+';
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
|
|
SEQ_PUT_HEX_FIELD_RET(s, S);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
|
|
SEQ_PUT_HEX_FIELD_RET(s, T);
|
|
break;
|
|
case TRACE_SPECIAL:
|
|
case TRACE_STACK:
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
|
|
break;
|
|
}
|
|
SEQ_PUT_FIELD_RET(s, newline);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int print_bin_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
|
|
entry = iter->ent;
|
|
|
|
SEQ_PUT_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_FIELD_RET(s, entry->cpu);
|
|
SEQ_PUT_FIELD_RET(s, entry->t);
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN:
|
|
SEQ_PUT_FIELD_RET(s, entry->fn.ip);
|
|
SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
|
|
break;
|
|
case TRACE_CTX:
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
|
|
SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
|
|
break;
|
|
case TRACE_SPECIAL:
|
|
case TRACE_STACK:
|
|
SEQ_PUT_FIELD_RET(s, entry->special.arg1);
|
|
SEQ_PUT_FIELD_RET(s, entry->special.arg2);
|
|
SEQ_PUT_FIELD_RET(s, entry->special.arg3);
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int trace_empty(struct trace_iterator *iter)
|
|
{
|
|
struct trace_array_cpu *data;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
data = iter->tr->data[cpu];
|
|
|
|
if (head_page(data) && data->trace_idx &&
|
|
(data->trace_tail != data->trace_head ||
|
|
data->trace_tail_idx != data->trace_head_idx))
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int print_trace_line(struct trace_iterator *iter)
|
|
{
|
|
if (trace_flags & TRACE_ITER_BIN)
|
|
return print_bin_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_HEX)
|
|
return print_hex_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_RAW)
|
|
return print_raw_fmt(iter);
|
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
|
|
return print_lat_fmt(iter, iter->idx, iter->cpu);
|
|
|
|
return print_trace_fmt(iter);
|
|
}
|
|
|
|
static int s_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_iterator *iter = v;
|
|
|
|
if (iter->ent == NULL) {
|
|
if (iter->tr) {
|
|
seq_printf(m, "# tracer: %s\n", iter->trace->name);
|
|
seq_puts(m, "#\n");
|
|
}
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
|
|
/* print nothing if the buffers are empty */
|
|
if (trace_empty(iter))
|
|
return 0;
|
|
print_trace_header(m, iter);
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_lat_help_header(m);
|
|
} else {
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_func_help_header(m);
|
|
}
|
|
} else {
|
|
print_trace_line(iter);
|
|
trace_print_seq(m, &iter->seq);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations tracer_seq_ops = {
|
|
.start = s_start,
|
|
.next = s_next,
|
|
.stop = s_stop,
|
|
.show = s_show,
|
|
};
|
|
|
|
static struct trace_iterator *
|
|
__tracing_open(struct inode *inode, struct file *file, int *ret)
|
|
{
|
|
struct trace_iterator *iter;
|
|
|
|
if (tracing_disabled) {
|
|
*ret = -ENODEV;
|
|
return NULL;
|
|
}
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter) {
|
|
*ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (current_trace && current_trace->print_max)
|
|
iter->tr = &max_tr;
|
|
else
|
|
iter->tr = inode->i_private;
|
|
iter->trace = current_trace;
|
|
iter->pos = -1;
|
|
|
|
/* TODO stop tracer */
|
|
*ret = seq_open(file, &tracer_seq_ops);
|
|
if (!*ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = iter;
|
|
|
|
/* stop the trace while dumping */
|
|
if (iter->tr->ctrl)
|
|
tracer_enabled = 0;
|
|
|
|
if (iter->trace && iter->trace->open)
|
|
iter->trace->open(iter);
|
|
} else {
|
|
kfree(iter);
|
|
iter = NULL;
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
out:
|
|
return iter;
|
|
}
|
|
|
|
int tracing_open_generic(struct inode *inode, struct file *filp)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
filp->private_data = inode->i_private;
|
|
return 0;
|
|
}
|
|
|
|
int tracing_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct trace_iterator *iter = m->private;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (iter->trace && iter->trace->close)
|
|
iter->trace->close(iter);
|
|
|
|
/* reenable tracing if it was previously enabled */
|
|
if (iter->tr->ctrl)
|
|
tracer_enabled = 1;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
seq_release(inode, file);
|
|
kfree(iter);
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
__tracing_open(inode, file, &ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tracing_lt_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter;
|
|
int ret;
|
|
|
|
iter = __tracing_open(inode, file, &ret);
|
|
|
|
if (!ret)
|
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct tracer *t = m->private;
|
|
|
|
(*pos)++;
|
|
|
|
if (t)
|
|
t = t->next;
|
|
|
|
m->private = t;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct tracer *t = m->private;
|
|
loff_t l = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (; t && l < *pos; t = t_next(m, t, &l))
|
|
;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct tracer *t = v;
|
|
|
|
if (!t)
|
|
return 0;
|
|
|
|
seq_printf(m, "%s", t->name);
|
|
if (t->next)
|
|
seq_putc(m, ' ');
|
|
else
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations show_traces_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int show_traces_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
ret = seq_open(file, &show_traces_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = trace_types;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct file_operations tracing_fops = {
|
|
.open = tracing_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = tracing_release,
|
|
};
|
|
|
|
static struct file_operations tracing_lt_fops = {
|
|
.open = tracing_lt_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = tracing_release,
|
|
};
|
|
|
|
static struct file_operations show_traces_fops = {
|
|
.open = show_traces_open,
|
|
.read = seq_read,
|
|
.release = seq_release,
|
|
};
|
|
|
|
/*
|
|
* Only trace on a CPU if the bitmask is set:
|
|
*/
|
|
static cpumask_t tracing_cpumask = CPU_MASK_ALL;
|
|
|
|
/*
|
|
* When tracing/tracing_cpu_mask is modified then this holds
|
|
* the new bitmask we are about to install:
|
|
*/
|
|
static cpumask_t tracing_cpumask_new;
|
|
|
|
/*
|
|
* The tracer itself will not take this lock, but still we want
|
|
* to provide a consistent cpumask to user-space:
|
|
*/
|
|
static DEFINE_MUTEX(tracing_cpumask_update_lock);
|
|
|
|
/*
|
|
* Temporary storage for the character representation of the
|
|
* CPU bitmask (and one more byte for the newline):
|
|
*/
|
|
static char mask_str[NR_CPUS + 1];
|
|
|
|
static ssize_t
|
|
tracing_cpumask_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int len;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
|
|
len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
|
|
if (count - len < 2) {
|
|
count = -EINVAL;
|
|
goto out_err;
|
|
}
|
|
len += sprintf(mask_str + len, "\n");
|
|
count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
|
|
|
|
out_err:
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int err, cpu;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
|
|
if (err)
|
|
goto err_unlock;
|
|
|
|
raw_local_irq_disable();
|
|
__raw_spin_lock(&ftrace_max_lock);
|
|
for_each_possible_cpu(cpu) {
|
|
/*
|
|
* Increase/decrease the disabled counter if we are
|
|
* about to flip a bit in the cpumask:
|
|
*/
|
|
if (cpu_isset(cpu, tracing_cpumask) &&
|
|
!cpu_isset(cpu, tracing_cpumask_new)) {
|
|
atomic_inc(&global_trace.data[cpu]->disabled);
|
|
}
|
|
if (!cpu_isset(cpu, tracing_cpumask) &&
|
|
cpu_isset(cpu, tracing_cpumask_new)) {
|
|
atomic_dec(&global_trace.data[cpu]->disabled);
|
|
}
|
|
}
|
|
__raw_spin_unlock(&ftrace_max_lock);
|
|
raw_local_irq_enable();
|
|
|
|
tracing_cpumask = tracing_cpumask_new;
|
|
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return count;
|
|
|
|
err_unlock:
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct file_operations tracing_cpumask_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_cpumask_read,
|
|
.write = tracing_cpumask_write,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char *buf;
|
|
int r = 0;
|
|
int len = 0;
|
|
int i;
|
|
|
|
/* calulate max size */
|
|
for (i = 0; trace_options[i]; i++) {
|
|
len += strlen(trace_options[i]);
|
|
len += 3; /* "no" and space */
|
|
}
|
|
|
|
/* +2 for \n and \0 */
|
|
buf = kmalloc(len + 2, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
if (trace_flags & (1 << i))
|
|
r += sprintf(buf + r, "%s ", trace_options[i]);
|
|
else
|
|
r += sprintf(buf + r, "no%s ", trace_options[i]);
|
|
}
|
|
|
|
r += sprintf(buf + r, "\n");
|
|
WARN_ON(r >= len + 2);
|
|
|
|
r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
|
|
kfree(buf);
|
|
|
|
return r;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64];
|
|
char *cmp = buf;
|
|
int neg = 0;
|
|
int i;
|
|
|
|
if (cnt > 63)
|
|
cnt = 63;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
if (strncmp(buf, "no", 2) == 0) {
|
|
neg = 1;
|
|
cmp += 2;
|
|
}
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
int len = strlen(trace_options[i]);
|
|
|
|
if (strncmp(cmp, trace_options[i], len) == 0) {
|
|
if (neg)
|
|
trace_flags &= ~(1 << i);
|
|
else
|
|
trace_flags |= (1 << i);
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* If no option could be set, return an error:
|
|
*/
|
|
if (!trace_options[i])
|
|
return -EINVAL;
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static struct file_operations tracing_iter_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_iter_ctrl_read,
|
|
.write = tracing_iter_ctrl_write,
|
|
};
|
|
|
|
static const char readme_msg[] =
|
|
"tracing mini-HOWTO:\n\n"
|
|
"# mkdir /debug\n"
|
|
"# mount -t debugfs nodev /debug\n\n"
|
|
"# cat /debug/tracing/available_tracers\n"
|
|
"wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
|
|
"# cat /debug/tracing/current_tracer\n"
|
|
"none\n"
|
|
"# echo sched_switch > /debug/tracing/current_tracer\n"
|
|
"# cat /debug/tracing/current_tracer\n"
|
|
"sched_switch\n"
|
|
"# cat /debug/tracing/iter_ctrl\n"
|
|
"noprint-parent nosym-offset nosym-addr noverbose\n"
|
|
"# echo print-parent > /debug/tracing/iter_ctrl\n"
|
|
"# echo 1 > /debug/tracing/tracing_enabled\n"
|
|
"# cat /debug/tracing/trace > /tmp/trace.txt\n"
|
|
"echo 0 > /debug/tracing/tracing_enabled\n"
|
|
;
|
|
|
|
static ssize_t
|
|
tracing_readme_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return simple_read_from_buffer(ubuf, cnt, ppos,
|
|
readme_msg, strlen(readme_msg));
|
|
}
|
|
|
|
static struct file_operations tracing_readme_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_readme_read,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_ctrl_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = sprintf(buf, "%ld\n", tr->ctrl);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_ctrl_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
long val;
|
|
char buf[64];
|
|
|
|
if (cnt > 63)
|
|
cnt = 63;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
val = simple_strtoul(buf, NULL, 10);
|
|
|
|
val = !!val;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (tr->ctrl ^ val) {
|
|
if (val)
|
|
tracer_enabled = 1;
|
|
else
|
|
tracer_enabled = 0;
|
|
|
|
tr->ctrl = val;
|
|
|
|
if (current_trace && current_trace->ctrl_update)
|
|
current_trace->ctrl_update(tr);
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_set_trace_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[max_tracer_type_len+2];
|
|
int r;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (current_trace)
|
|
r = sprintf(buf, "%s\n", current_trace->name);
|
|
else
|
|
r = sprintf(buf, "\n");
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct tracer *t;
|
|
char buf[max_tracer_type_len+1];
|
|
int i;
|
|
|
|
if (cnt > max_tracer_type_len)
|
|
cnt = max_tracer_type_len;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
/* strip ending whitespace. */
|
|
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
|
|
buf[i] = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (t = trace_types; t; t = t->next) {
|
|
if (strcmp(t->name, buf) == 0)
|
|
break;
|
|
}
|
|
if (!t || t == current_trace)
|
|
goto out;
|
|
|
|
if (current_trace && current_trace->reset)
|
|
current_trace->reset(tr);
|
|
|
|
current_trace = t;
|
|
if (t->init)
|
|
t->init(tr);
|
|
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long *ptr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = snprintf(buf, 64, "%ld\n",
|
|
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
|
|
if (r > 64)
|
|
r = 64;
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
long *ptr = filp->private_data;
|
|
long val;
|
|
char buf[64];
|
|
|
|
if (cnt > 63)
|
|
cnt = 63;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
val = simple_strtoul(buf, NULL, 10);
|
|
|
|
*ptr = val * 1000;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static atomic_t tracing_reader;
|
|
|
|
static int tracing_open_pipe(struct inode *inode, struct file *filp)
|
|
{
|
|
struct trace_iterator *iter;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
/* We only allow for reader of the pipe */
|
|
if (atomic_inc_return(&tracing_reader) != 1) {
|
|
atomic_dec(&tracing_reader);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* create a buffer to store the information to pass to userspace */
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
iter->tr = &global_trace;
|
|
|
|
filp->private_data = iter;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_release_pipe(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter = file->private_data;
|
|
|
|
kfree(iter);
|
|
atomic_dec(&tracing_reader);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int
|
|
tracing_poll_pipe(struct file *filp, poll_table *poll_table)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
|
|
if (trace_flags & TRACE_ITER_BLOCK) {
|
|
/*
|
|
* Always select as readable when in blocking mode
|
|
*/
|
|
return POLLIN | POLLRDNORM;
|
|
}
|
|
else {
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
poll_wait(filp, &trace_wait, poll_table);
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Consumer reader.
|
|
*/
|
|
static ssize_t
|
|
tracing_read_pipe(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
struct trace_array_cpu *data;
|
|
static cpumask_t mask;
|
|
static int start;
|
|
unsigned long flags;
|
|
#ifdef CONFIG_FTRACE
|
|
int ftrace_save;
|
|
#endif
|
|
int read = 0;
|
|
int cpu;
|
|
int len;
|
|
int ret;
|
|
|
|
/* return any leftover data */
|
|
if (iter->seq.len > start) {
|
|
len = iter->seq.len - start;
|
|
if (cnt > len)
|
|
cnt = len;
|
|
ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt);
|
|
if (ret)
|
|
cnt = -EFAULT;
|
|
|
|
start += len;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
trace_seq_reset(&iter->seq);
|
|
start = 0;
|
|
|
|
while (trace_empty(iter)) {
|
|
if (!(trace_flags & TRACE_ITER_BLOCK))
|
|
return -EWOULDBLOCK;
|
|
/*
|
|
* This is a make-shift waitqueue. The reason we don't use
|
|
* an actual wait queue is because:
|
|
* 1) we only ever have one waiter
|
|
* 2) the tracing, traces all functions, we don't want
|
|
* the overhead of calling wake_up and friends
|
|
* (and tracing them too)
|
|
* Anyway, this is really very primitive wakeup.
|
|
*/
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
iter->tr->waiter = current;
|
|
|
|
/* sleep for one second, and try again. */
|
|
schedule_timeout(HZ);
|
|
|
|
iter->tr->waiter = NULL;
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
/*
|
|
* We block until we read something and tracing is disabled.
|
|
* We still block if tracing is disabled, but we have never
|
|
* read anything. This allows a user to cat this file, and
|
|
* then enable tracing. But after we have read something,
|
|
* we give an EOF when tracing is again disabled.
|
|
*
|
|
* iter->pos will be 0 if we haven't read anything.
|
|
*/
|
|
if (!tracer_enabled && iter->pos)
|
|
break;
|
|
|
|
continue;
|
|
}
|
|
|
|
/* stop when tracing is finished */
|
|
if (trace_empty(iter))
|
|
return 0;
|
|
|
|
if (cnt >= PAGE_SIZE)
|
|
cnt = PAGE_SIZE - 1;
|
|
|
|
memset(iter, 0, sizeof(*iter));
|
|
iter->tr = &global_trace;
|
|
iter->pos = -1;
|
|
|
|
/*
|
|
* We need to stop all tracing on all CPUS to read the
|
|
* the next buffer. This is a bit expensive, but is
|
|
* not done often. We fill all what we can read,
|
|
* and then release the locks again.
|
|
*/
|
|
|
|
cpus_clear(mask);
|
|
local_irq_save(flags);
|
|
#ifdef CONFIG_FTRACE
|
|
ftrace_save = ftrace_enabled;
|
|
ftrace_enabled = 0;
|
|
#endif
|
|
smp_wmb();
|
|
for_each_possible_cpu(cpu) {
|
|
data = iter->tr->data[cpu];
|
|
|
|
if (!head_page(data) || !data->trace_idx)
|
|
continue;
|
|
|
|
atomic_inc(&data->disabled);
|
|
cpu_set(cpu, mask);
|
|
}
|
|
|
|
for_each_cpu_mask(cpu, mask) {
|
|
data = iter->tr->data[cpu];
|
|
__raw_spin_lock(&data->lock);
|
|
}
|
|
|
|
while (find_next_entry_inc(iter) != NULL) {
|
|
int len = iter->seq.len;
|
|
|
|
ret = print_trace_line(iter);
|
|
if (!ret) {
|
|
/* don't print partial lines */
|
|
iter->seq.len = len;
|
|
break;
|
|
}
|
|
|
|
trace_consume(iter);
|
|
|
|
if (iter->seq.len >= cnt)
|
|
break;
|
|
}
|
|
|
|
for_each_cpu_mask(cpu, mask) {
|
|
data = iter->tr->data[cpu];
|
|
__raw_spin_unlock(&data->lock);
|
|
}
|
|
|
|
for_each_cpu_mask(cpu, mask) {
|
|
data = iter->tr->data[cpu];
|
|
atomic_dec(&data->disabled);
|
|
}
|
|
#ifdef CONFIG_FTRACE
|
|
ftrace_enabled = ftrace_save;
|
|
#endif
|
|
local_irq_restore(flags);
|
|
|
|
/* Now copy what we have to the user */
|
|
read = iter->seq.len;
|
|
if (read > cnt)
|
|
read = cnt;
|
|
|
|
ret = copy_to_user(ubuf, iter->seq.buffer, read);
|
|
|
|
if (read < iter->seq.len)
|
|
start = read;
|
|
else
|
|
trace_seq_reset(&iter->seq);
|
|
|
|
if (ret)
|
|
read = -EFAULT;
|
|
|
|
return read;
|
|
}
|
|
|
|
static struct file_operations tracing_max_lat_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_max_lat_read,
|
|
.write = tracing_max_lat_write,
|
|
};
|
|
|
|
static struct file_operations tracing_ctrl_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_ctrl_read,
|
|
.write = tracing_ctrl_write,
|
|
};
|
|
|
|
static struct file_operations set_tracer_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_set_trace_read,
|
|
.write = tracing_set_trace_write,
|
|
};
|
|
|
|
static struct file_operations tracing_pipe_fops = {
|
|
.open = tracing_open_pipe,
|
|
.poll = tracing_poll_pipe,
|
|
.read = tracing_read_pipe,
|
|
.release = tracing_release_pipe,
|
|
};
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
static ssize_t
|
|
tracing_read_long(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long *p = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = sprintf(buf, "%ld\n", *p);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static struct file_operations tracing_read_long_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_read_long,
|
|
};
|
|
#endif
|
|
|
|
static struct dentry *d_tracer;
|
|
|
|
struct dentry *tracing_init_dentry(void)
|
|
{
|
|
static int once;
|
|
|
|
if (d_tracer)
|
|
return d_tracer;
|
|
|
|
d_tracer = debugfs_create_dir("tracing", NULL);
|
|
|
|
if (!d_tracer && !once) {
|
|
once = 1;
|
|
pr_warning("Could not create debugfs directory 'tracing'\n");
|
|
return NULL;
|
|
}
|
|
|
|
return d_tracer;
|
|
}
|
|
|
|
#ifdef CONFIG_FTRACE_SELFTEST
|
|
/* Let selftest have access to static functions in this file */
|
|
#include "trace_selftest.c"
|
|
#endif
|
|
|
|
static __init void tracer_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
entry = debugfs_create_file("tracing_enabled", 0644, d_tracer,
|
|
&global_trace, &tracing_ctrl_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
|
|
|
|
entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
|
|
NULL, &tracing_iter_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
|
|
NULL, &tracing_cpumask_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
|
|
|
|
entry = debugfs_create_file("latency_trace", 0444, d_tracer,
|
|
&global_trace, &tracing_lt_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'latency_trace' entry\n");
|
|
|
|
entry = debugfs_create_file("trace", 0444, d_tracer,
|
|
&global_trace, &tracing_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'trace' entry\n");
|
|
|
|
entry = debugfs_create_file("available_tracers", 0444, d_tracer,
|
|
&global_trace, &show_traces_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'trace' entry\n");
|
|
|
|
entry = debugfs_create_file("current_tracer", 0444, d_tracer,
|
|
&global_trace, &set_tracer_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'trace' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
|
|
&tracing_max_latency,
|
|
&tracing_max_lat_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'tracing_max_latency' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_thresh", 0644, d_tracer,
|
|
&tracing_thresh, &tracing_max_lat_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'tracing_threash' entry\n");
|
|
entry = debugfs_create_file("README", 0644, d_tracer,
|
|
NULL, &tracing_readme_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'README' entry\n");
|
|
|
|
entry = debugfs_create_file("trace_pipe", 0644, d_tracer,
|
|
NULL, &tracing_pipe_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'tracing_threash' entry\n");
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
|
|
&ftrace_update_tot_cnt,
|
|
&tracing_read_long_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'dyn_ftrace_total_info' entry\n");
|
|
#endif
|
|
}
|
|
|
|
/* dummy trace to disable tracing */
|
|
static struct tracer no_tracer __read_mostly =
|
|
{
|
|
.name = "none",
|
|
};
|
|
|
|
static int trace_alloc_page(void)
|
|
{
|
|
struct trace_array_cpu *data;
|
|
struct page *page, *tmp;
|
|
LIST_HEAD(pages);
|
|
void *array;
|
|
int i;
|
|
|
|
/* first allocate a page for each CPU */
|
|
for_each_possible_cpu(i) {
|
|
array = (void *)__get_free_page(GFP_KERNEL);
|
|
if (array == NULL) {
|
|
printk(KERN_ERR "tracer: failed to allocate page"
|
|
"for trace buffer!\n");
|
|
goto free_pages;
|
|
}
|
|
|
|
page = virt_to_page(array);
|
|
list_add(&page->lru, &pages);
|
|
|
|
/* Only allocate if we are actually using the max trace */
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
array = (void *)__get_free_page(GFP_KERNEL);
|
|
if (array == NULL) {
|
|
printk(KERN_ERR "tracer: failed to allocate page"
|
|
"for trace buffer!\n");
|
|
goto free_pages;
|
|
}
|
|
page = virt_to_page(array);
|
|
list_add(&page->lru, &pages);
|
|
#endif
|
|
}
|
|
|
|
/* Now that we successfully allocate a page per CPU, add them */
|
|
for_each_possible_cpu(i) {
|
|
data = global_trace.data[i];
|
|
data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
|
|
page = list_entry(pages.next, struct page, lru);
|
|
list_del_init(&page->lru);
|
|
list_add_tail(&page->lru, &data->trace_pages);
|
|
ClearPageLRU(page);
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
data = max_tr.data[i];
|
|
data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
|
|
page = list_entry(pages.next, struct page, lru);
|
|
list_del_init(&page->lru);
|
|
list_add_tail(&page->lru, &data->trace_pages);
|
|
SetPageLRU(page);
|
|
#endif
|
|
}
|
|
global_trace.entries += ENTRIES_PER_PAGE;
|
|
|
|
return 0;
|
|
|
|
free_pages:
|
|
list_for_each_entry_safe(page, tmp, &pages, lru) {
|
|
list_del_init(&page->lru);
|
|
__free_page(page);
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
|
|
__init static int tracer_alloc_buffers(void)
|
|
{
|
|
struct trace_array_cpu *data;
|
|
void *array;
|
|
struct page *page;
|
|
int pages = 0;
|
|
int ret = -ENOMEM;
|
|
int i;
|
|
|
|
global_trace.ctrl = tracer_enabled;
|
|
|
|
/* Allocate the first page for all buffers */
|
|
for_each_possible_cpu(i) {
|
|
data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
|
|
max_tr.data[i] = &per_cpu(max_data, i);
|
|
|
|
array = (void *)__get_free_page(GFP_KERNEL);
|
|
if (array == NULL) {
|
|
printk(KERN_ERR "tracer: failed to allocate page"
|
|
"for trace buffer!\n");
|
|
goto free_buffers;
|
|
}
|
|
|
|
/* set the array to the list */
|
|
INIT_LIST_HEAD(&data->trace_pages);
|
|
page = virt_to_page(array);
|
|
list_add(&page->lru, &data->trace_pages);
|
|
/* use the LRU flag to differentiate the two buffers */
|
|
ClearPageLRU(page);
|
|
|
|
/* Only allocate if we are actually using the max trace */
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
array = (void *)__get_free_page(GFP_KERNEL);
|
|
if (array == NULL) {
|
|
printk(KERN_ERR "tracer: failed to allocate page"
|
|
"for trace buffer!\n");
|
|
goto free_buffers;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
|
|
page = virt_to_page(array);
|
|
list_add(&page->lru, &max_tr.data[i]->trace_pages);
|
|
SetPageLRU(page);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Since we allocate by orders of pages, we may be able to
|
|
* round up a bit.
|
|
*/
|
|
global_trace.entries = ENTRIES_PER_PAGE;
|
|
pages++;
|
|
|
|
while (global_trace.entries < trace_nr_entries) {
|
|
if (trace_alloc_page())
|
|
break;
|
|
pages++;
|
|
}
|
|
max_tr.entries = global_trace.entries;
|
|
|
|
pr_info("tracer: %d pages allocated for %ld",
|
|
pages, trace_nr_entries);
|
|
pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE);
|
|
pr_info(" actual entries %ld\n", global_trace.entries);
|
|
|
|
tracer_init_debugfs();
|
|
|
|
trace_init_cmdlines();
|
|
|
|
register_tracer(&no_tracer);
|
|
current_trace = &no_tracer;
|
|
|
|
/* All seems OK, enable tracing */
|
|
tracing_disabled = 0;
|
|
|
|
return 0;
|
|
|
|
free_buffers:
|
|
for (i-- ; i >= 0; i--) {
|
|
struct page *page, *tmp;
|
|
struct trace_array_cpu *data = global_trace.data[i];
|
|
|
|
if (data) {
|
|
list_for_each_entry_safe(page, tmp,
|
|
&data->trace_pages, lru) {
|
|
list_del_init(&page->lru);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
data = max_tr.data[i];
|
|
if (data) {
|
|
list_for_each_entry_safe(page, tmp,
|
|
&data->trace_pages, lru) {
|
|
list_del_init(&page->lru);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
return ret;
|
|
}
|
|
fs_initcall(tracer_alloc_buffers);
|