AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

tracing: Do not stop recording comms if the trace file is being read

Browse Source 
commit 4fdd595e4f9a1ff6d93ec702eaecae451cfc6591 upstream.

A while ago, when the "trace" file was opened, tracing was stopped, and
code was added to stop recording the comms to saved_cmdlines, for mapping
of the pids to the task name.

Code has been added that only records the comm if a trace event occurred,
and there's no reason to not trace it if the trace file is opened.

Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5c ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Steven Rostedt (VMware) 2021-06-17 14:32:34 -04:00 committed by Greg Kroah-Hartman
parent adb3849ed8
commit b313bd944d
1 changed files with 0 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
kernel/trace/trace.c
View File

@ -2195,9 +2195,6 @@ struct saved_cmdlines_buffer {
}; };
static struct saved_cmdlines_buffer *savedcmd; static struct saved_cmdlines_buffer *savedcmd;
/* temporary disable recording */
static atomic_t trace_record_taskinfo_disabled __read_mostly;
static inline char *get_saved_cmdlines(int idx) static inline char *get_saved_cmdlines(int idx)
{ {
return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
@ -3683,9 +3680,6 @@ static void *s_start(struct seq_file *m, loff_t *pos)
return ERR_PTR(-EBUSY); return ERR_PTR(-EBUSY);
#endif #endif
if (!iter->snapshot)
atomic_inc(&trace_record_taskinfo_disabled);
if (*pos != iter->pos) { if (*pos != iter->pos) {
iter->ent = NULL; iter->ent = NULL;
iter->cpu = 0; iter->cpu = 0;
@ -3728,9 +3722,6 @@ static void s_stop(struct seq_file *m, void *p)
return; return;
#endif #endif
if (!iter->snapshot)
atomic_dec(&trace_record_taskinfo_disabled);
trace_access_unlock(iter->cpu_file); trace_access_unlock(iter->cpu_file);
trace_event_read_unlock(); trace_event_read_unlock();
} }