diff options
| author | Dave Airlie <airlied@redhat.com> | 2010-12-22 09:48:54 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2010-12-22 09:48:54 +1000 |
| commit | ae09f09e94d755ed45c58b695675636c0ec53f9e (patch) | |
| tree | 77cb9bac7d81f5b1250b8638a007e10c17b600af /kernel/trace/trace.c | |
| parent | 1d99e5c57255d188773fb437391df24fe8faf575 (diff) | |
| parent | 5909a77ac62cc042f94bd262016cf468a2f96022 (diff) | |
Merge remote branch 'intel/drm-intel-next' of /ssd/git/drm-next into drm-core-next
* 'intel/drm-intel-next' of /ssd/git/drm-next: (771 commits)
drm/i915: Undo "Uncouple render/power ctx before suspending"
drm/i915: Allow the application to choose the constant addressing mode
drm/i915: dynamic render p-state support for Sandy Bridge
drm/i915: Enable EI mode for RCx decision making on Sandybridge
drm/i915/sdvo: Border and stall select became test bits in gen5
drm/i915: Add Guess-o-matic for pageflip timestamping.
drm/i915: Add support for precise vblank timestamping (v2)
drm/i915: Add frame buffer compression on Sandybridge
drm/i915: Add self-refresh support on Sandybridge
drm/i915: Wait for vblank before unpinning old fb
Revert "drm/i915: Avoid using PIPE_CONTROL on Ironlake"
drm/i915: Pass clock limits down to PLL matcher
drm/i915: Poll for seqno completion if IRQ is disabled
drm/i915/ringbuffer: Make IRQ refcnting atomic
agp/intel: Fix missed cached memory flags setting in i965_write_entry()
drm/i915/sdvo: Only use the SDVO pin if it is in the valid range
drm/i915: Enable RC6 autodownclocking on Sandybridge
drm/i915: Terminate the FORCE WAKE after we have finished reading
drm/i915/gtt: Clear the cachelines upon resume
drm/i915: Restore GTT mapping first upon resume
...
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 042084157980..c380612273bf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1283,6 +1283,8 @@ void trace_dump_stack(void) __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count()); } +static DEFINE_PER_CPU(int, user_stack_count); + void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) { @@ -1301,6 +1303,18 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) if (unlikely(in_nmi())) return; + /* + * prevent recursion, since the user stack tracing may + * trigger other kernel events. + */ + preempt_disable(); + if (__this_cpu_read(user_stack_count)) + goto out; + + __this_cpu_inc(user_stack_count); + + + event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, sizeof(*entry), flags, pc); if (!event) @@ -1318,6 +1332,11 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) save_stack_trace_user(&trace); if (!filter_check_discard(call, entry, buffer, event)) ring_buffer_unlock_commit(buffer, event); + + __this_cpu_dec(user_stack_count); + + out: + preempt_enable(); } #ifdef UNUSED |