lkml.org 
[lkml]   [2013]   [Nov]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 10/13] tracing/uprobes: Fetch args before reserving a ring buffer
Hi Namhyung,

On 11/04, Namhyung Kim wrote:
>
> >>
> >> + if (atomic_dec_and_test(&uprobe_buffer_ref)) {
> >> + free_percpu(uprobe_cpu_buffer);
> >> + uprobe_cpu_buffer = NULL;
> >> + }
> >> +
> >> WARN_ON(!uprobe_filter_is_empty(&tu->filter));
> >
> > Do we really need atomic_t? probe_event_enable/disable is called under
> > event_mutex and we rely on this fact anyway.
>
> Looking at the code, it seems probe_event_enable/disable() is called
> without event_mutex when it called from sys_perf_event_open().

Where?

__ftrace_set_clr_event(), perf_trace_init() or perf_trace_destroy()
hold event_mutex. We rely on this fact anyway.

Oleg.



\
 
 \ /
  Last update: 2013-11-04 16:01    [W:0.058 / U:3.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site