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tracing: Move open coded processing of tgid_map into helper function

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In preparation of moving the saved_cmdlines logic out of trace.c and into
trace_sched_switch.c, replace the open coded manipulation of tgid_map in
set_tracer_flag() into a helper function trace_alloc_tgid_map() so that it
can be easily moved into trace_sched_switch.c without changing existing
functions in trace.c.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.338116216@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google) 2024-02-20 09:06:15 -05:00
parent 0b18c852cc
commit e85d471c2b
1 changed files with 23 additions and 15 deletions
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38
kernel/trace/trace.c
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@ -5453,10 +5453,31 @@ int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
return 0;
}
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
static int trace_alloc_tgid_map(void)
{
int *map;
if (tgid_map)
return 0;
tgid_map_max = pid_max;
map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
GFP_KERNEL);
if (!map)
return -ENOMEM;
/*
* Pairs with smp_load_acquire() in
* trace_find_tgid_ptr() to ensure that if it observes
* the tgid_map we just allocated then it also observes
* the corresponding tgid_map_max value.
*/
smp_store_release(&tgid_map, map);
return 0;
}
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
if ((mask == TRACE_ITER_RECORD_TGID) ||
(mask == TRACE_ITER_RECORD_CMD))
lockdep_assert_held(&event_mutex);
@ -5479,20 +5500,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
trace_event_enable_cmd_record(enabled);
if (mask == TRACE_ITER_RECORD_TGID) {
if (!tgid_map) {
tgid_map_max = pid_max;
map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
GFP_KERNEL);
/*
* Pairs with smp_load_acquire() in
* trace_find_tgid_ptr() to ensure that if it observes
* the tgid_map we just allocated then it also observes
* the corresponding tgid_map_max value.
*/
smp_store_release(&tgid_map, map);
}
if (!tgid_map) {
if (trace_alloc_tgid_map() < 0) {
tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
return -ENOMEM;
}