Vince Weaver 4ec8363dfc perf_events: Fix perf buffer watermark setting ... Since 2.6.36 (specifically commit d57e34fdd6 ("perf: Simplify the ring-buffer logic: make perf_buffer_alloc() do everything needed"), the perf_buffer_init_code() has been mis-setting the buffer watermark if perf_event_attr.wakeup_events has a non-zero value. This is because perf_event_attr.wakeup_events is a union with perf_event_attr.wakeup_watermark. This commit re-enables the check for perf_event_attr.watermark being set before continuing with setting a non-default watermark. This bug is most noticable when you are trying to use PERF_IOC_REFRESH with a value larger than one and perf_event_attr.wakeup_events is set to one. In this case the buffer watermark will be set to 1 and you will get extraneous POLL_IN overflows rather than POLL_HUP as expected. [ avoid using attr.wakeup_events when attr.watermark is set ] Signed-off-by: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106011506390.5384@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar <mingo@elte.hu>		2011-07-01 11:06:32 +02:00
..
core.c	perf_events: Fix perf buffer watermark setting	2011-07-01 11:06:32 +02:00
hw_breakpoint.c	hw breakpoints: Move to kernel/events/	2011-05-03 15:26:43 +02:00
internal.h	perf: Split up buffer handling from core code	2011-06-09 12:57:54 +02:00
Makefile	perf: Split up buffer handling from core code	2011-06-09 12:57:54 +02:00
ring_buffer.c	perf_events: Fix perf buffer watermark setting	2011-07-01 11:06:32 +02:00