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linux/fs/fscache/stats.c
David Howells 5753c44188 FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phase
Permit the operations to retrieve data from the cache or to allocate space in
the cache for future writes to be interrupted whilst they're waiting for
permission for the operation to proceed.  Typically this wait occurs whilst the
cache object is being looked up on disk in the background.

If an interruption occurs, and the operation has not yet been given the
go-ahead to run, the operation is dequeued and cancelled, and control returns
to the read operation of the netfs routine with none of the requested pages
having been read or in any way marked as known by the cache.

This means that the initial wait is done interruptibly rather than
uninterruptibly.

In addition, extra stats values are made available to show the number of ops
cancelled and the number of cache space allocations interrupted.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:11:19 +00:00

254 lines
8.4 KiB
C

/* FS-Cache statistics
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define FSCACHE_DEBUG_LEVEL THREAD
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
/*
* operation counters
*/
atomic_t fscache_n_op_pend;
atomic_t fscache_n_op_run;
atomic_t fscache_n_op_enqueue;
atomic_t fscache_n_op_requeue;
atomic_t fscache_n_op_deferred_release;
atomic_t fscache_n_op_release;
atomic_t fscache_n_op_gc;
atomic_t fscache_n_op_cancelled;
atomic_t fscache_n_attr_changed;
atomic_t fscache_n_attr_changed_ok;
atomic_t fscache_n_attr_changed_nobufs;
atomic_t fscache_n_attr_changed_nomem;
atomic_t fscache_n_attr_changed_calls;
atomic_t fscache_n_allocs;
atomic_t fscache_n_allocs_ok;
atomic_t fscache_n_allocs_wait;
atomic_t fscache_n_allocs_nobufs;
atomic_t fscache_n_allocs_intr;
atomic_t fscache_n_alloc_ops;
atomic_t fscache_n_alloc_op_waits;
atomic_t fscache_n_retrievals;
atomic_t fscache_n_retrievals_ok;
atomic_t fscache_n_retrievals_wait;
atomic_t fscache_n_retrievals_nodata;
atomic_t fscache_n_retrievals_nobufs;
atomic_t fscache_n_retrievals_intr;
atomic_t fscache_n_retrievals_nomem;
atomic_t fscache_n_retrieval_ops;
atomic_t fscache_n_retrieval_op_waits;
atomic_t fscache_n_stores;
atomic_t fscache_n_stores_ok;
atomic_t fscache_n_stores_again;
atomic_t fscache_n_stores_nobufs;
atomic_t fscache_n_stores_oom;
atomic_t fscache_n_store_ops;
atomic_t fscache_n_store_calls;
atomic_t fscache_n_marks;
atomic_t fscache_n_uncaches;
atomic_t fscache_n_acquires;
atomic_t fscache_n_acquires_null;
atomic_t fscache_n_acquires_no_cache;
atomic_t fscache_n_acquires_ok;
atomic_t fscache_n_acquires_nobufs;
atomic_t fscache_n_acquires_oom;
atomic_t fscache_n_updates;
atomic_t fscache_n_updates_null;
atomic_t fscache_n_updates_run;
atomic_t fscache_n_relinquishes;
atomic_t fscache_n_relinquishes_null;
atomic_t fscache_n_relinquishes_waitcrt;
atomic_t fscache_n_cookie_index;
atomic_t fscache_n_cookie_data;
atomic_t fscache_n_cookie_special;
atomic_t fscache_n_object_alloc;
atomic_t fscache_n_object_no_alloc;
atomic_t fscache_n_object_lookups;
atomic_t fscache_n_object_lookups_negative;
atomic_t fscache_n_object_lookups_positive;
atomic_t fscache_n_object_created;
atomic_t fscache_n_object_avail;
atomic_t fscache_n_object_dead;
atomic_t fscache_n_checkaux_none;
atomic_t fscache_n_checkaux_okay;
atomic_t fscache_n_checkaux_update;
atomic_t fscache_n_checkaux_obsolete;
atomic_t fscache_n_cop_alloc_object;
atomic_t fscache_n_cop_lookup_object;
atomic_t fscache_n_cop_lookup_complete;
atomic_t fscache_n_cop_grab_object;
atomic_t fscache_n_cop_update_object;
atomic_t fscache_n_cop_drop_object;
atomic_t fscache_n_cop_put_object;
atomic_t fscache_n_cop_sync_cache;
atomic_t fscache_n_cop_attr_changed;
atomic_t fscache_n_cop_read_or_alloc_page;
atomic_t fscache_n_cop_read_or_alloc_pages;
atomic_t fscache_n_cop_allocate_page;
atomic_t fscache_n_cop_allocate_pages;
atomic_t fscache_n_cop_write_page;
atomic_t fscache_n_cop_uncache_page;
atomic_t fscache_n_cop_dissociate_pages;
/*
* display the general statistics
*/
static int fscache_stats_show(struct seq_file *m, void *v)
{
seq_puts(m, "FS-Cache statistics\n");
seq_printf(m, "Cookies: idx=%u dat=%u spc=%u\n",
atomic_read(&fscache_n_cookie_index),
atomic_read(&fscache_n_cookie_data),
atomic_read(&fscache_n_cookie_special));
seq_printf(m, "Objects: alc=%u nal=%u avl=%u ded=%u\n",
atomic_read(&fscache_n_object_alloc),
atomic_read(&fscache_n_object_no_alloc),
atomic_read(&fscache_n_object_avail),
atomic_read(&fscache_n_object_dead));
seq_printf(m, "ChkAux : non=%u ok=%u upd=%u obs=%u\n",
atomic_read(&fscache_n_checkaux_none),
atomic_read(&fscache_n_checkaux_okay),
atomic_read(&fscache_n_checkaux_update),
atomic_read(&fscache_n_checkaux_obsolete));
seq_printf(m, "Pages : mrk=%u unc=%u\n",
atomic_read(&fscache_n_marks),
atomic_read(&fscache_n_uncaches));
seq_printf(m, "Acquire: n=%u nul=%u noc=%u ok=%u nbf=%u"
" oom=%u\n",
atomic_read(&fscache_n_acquires),
atomic_read(&fscache_n_acquires_null),
atomic_read(&fscache_n_acquires_no_cache),
atomic_read(&fscache_n_acquires_ok),
atomic_read(&fscache_n_acquires_nobufs),
atomic_read(&fscache_n_acquires_oom));
seq_printf(m, "Lookups: n=%u neg=%u pos=%u crt=%u\n",
atomic_read(&fscache_n_object_lookups),
atomic_read(&fscache_n_object_lookups_negative),
atomic_read(&fscache_n_object_lookups_positive),
atomic_read(&fscache_n_object_created));
seq_printf(m, "Updates: n=%u nul=%u run=%u\n",
atomic_read(&fscache_n_updates),
atomic_read(&fscache_n_updates_null),
atomic_read(&fscache_n_updates_run));
seq_printf(m, "Relinqs: n=%u nul=%u wcr=%u\n",
atomic_read(&fscache_n_relinquishes),
atomic_read(&fscache_n_relinquishes_null),
atomic_read(&fscache_n_relinquishes_waitcrt));
seq_printf(m, "AttrChg: n=%u ok=%u nbf=%u oom=%u run=%u\n",
atomic_read(&fscache_n_attr_changed),
atomic_read(&fscache_n_attr_changed_ok),
atomic_read(&fscache_n_attr_changed_nobufs),
atomic_read(&fscache_n_attr_changed_nomem),
atomic_read(&fscache_n_attr_changed_calls));
seq_printf(m, "Allocs : n=%u ok=%u wt=%u nbf=%u int=%u\n",
atomic_read(&fscache_n_allocs),
atomic_read(&fscache_n_allocs_ok),
atomic_read(&fscache_n_allocs_wait),
atomic_read(&fscache_n_allocs_nobufs),
atomic_read(&fscache_n_allocs_intr));
seq_printf(m, "Allocs : ops=%u owt=%u\n",
atomic_read(&fscache_n_alloc_ops),
atomic_read(&fscache_n_alloc_op_waits));
seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
" int=%u oom=%u\n",
atomic_read(&fscache_n_retrievals),
atomic_read(&fscache_n_retrievals_ok),
atomic_read(&fscache_n_retrievals_wait),
atomic_read(&fscache_n_retrievals_nodata),
atomic_read(&fscache_n_retrievals_nobufs),
atomic_read(&fscache_n_retrievals_intr),
atomic_read(&fscache_n_retrievals_nomem));
seq_printf(m, "Retrvls: ops=%u owt=%u\n",
atomic_read(&fscache_n_retrieval_ops),
atomic_read(&fscache_n_retrieval_op_waits));
seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
atomic_read(&fscache_n_stores),
atomic_read(&fscache_n_stores_ok),
atomic_read(&fscache_n_stores_again),
atomic_read(&fscache_n_stores_nobufs),
atomic_read(&fscache_n_stores_oom));
seq_printf(m, "Stores : ops=%u run=%u\n",
atomic_read(&fscache_n_store_ops),
atomic_read(&fscache_n_store_calls));
seq_printf(m, "Ops : pend=%u run=%u enq=%u can=%u\n",
atomic_read(&fscache_n_op_pend),
atomic_read(&fscache_n_op_run),
atomic_read(&fscache_n_op_enqueue),
atomic_read(&fscache_n_op_cancelled));
seq_printf(m, "Ops : dfr=%u rel=%u gc=%u\n",
atomic_read(&fscache_n_op_deferred_release),
atomic_read(&fscache_n_op_release),
atomic_read(&fscache_n_op_gc));
seq_printf(m, "CacheOp: alo=%d luo=%d luc=%d gro=%d\n",
atomic_read(&fscache_n_cop_alloc_object),
atomic_read(&fscache_n_cop_lookup_object),
atomic_read(&fscache_n_cop_lookup_complete),
atomic_read(&fscache_n_cop_grab_object));
seq_printf(m, "CacheOp: upo=%d dro=%d pto=%d atc=%d syn=%d\n",
atomic_read(&fscache_n_cop_update_object),
atomic_read(&fscache_n_cop_drop_object),
atomic_read(&fscache_n_cop_put_object),
atomic_read(&fscache_n_cop_attr_changed),
atomic_read(&fscache_n_cop_sync_cache));
seq_printf(m, "CacheOp: rap=%d ras=%d alp=%d als=%d wrp=%d ucp=%d dsp=%d\n",
atomic_read(&fscache_n_cop_read_or_alloc_page),
atomic_read(&fscache_n_cop_read_or_alloc_pages),
atomic_read(&fscache_n_cop_allocate_page),
atomic_read(&fscache_n_cop_allocate_pages),
atomic_read(&fscache_n_cop_write_page),
atomic_read(&fscache_n_cop_uncache_page),
atomic_read(&fscache_n_cop_dissociate_pages));
return 0;
}
/*
* open "/proc/fs/fscache/stats" allowing provision of a statistical summary
*/
static int fscache_stats_open(struct inode *inode, struct file *file)
{
return single_open(file, fscache_stats_show, NULL);
}
const struct file_operations fscache_stats_fops = {
.owner = THIS_MODULE,
.open = fscache_stats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};