linux-toradex.git/kernel/events, branch v3.1-rc2

perf: Remove perf_event_attr::type check

2011-07-21T18:41:55+00:00

PMU type id can be allocated dynamically, so perf_event_attr::type check
when copying attribute from userspace to kernel is not valid.

Signed-off-by: Lin Ming 
Cc: Robert Richter 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1309421396-17438-4-git-send-email-ming.m.lin@intel.com
Signed-off-by: Ingo Molnar

perf: export perf_event_refresh() to modules

2011-07-01T09:06:40+00:00

KVM needs one-shot samples, since a PMC programmed to -X will fire after X
events and then again after 2^40 events (i.e. variable period).

Signed-off-by: Avi Kivity 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1309362157-6596-4-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar

perf: Add context field to perf_event

2011-07-01T09:06:38+00:00

The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure.  This is ugly and doesn't scale if a
single callback services many perf_events.

Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.

Signed-off-by: Avi Kivity 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar

perf: Remove the perf_output_begin(.sample) argument

2011-07-01T09:06:35+00:00

Since only samples call perf_output_sample() its much saner (and more
correct) to put the sample logic in there than in the
perf_output_begin()/perf_output_end() pair.

Saves a useless argument, reduces conditionals and shrinks
struct perf_output_handle, win!

Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@git.kernel.org
Signed-off-by: Ingo Molnar

perf: Remove the nmi parameter from the swevent and overflow interface

2011-07-01T09:06:35+00:00

The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra 
Cc: Michael Cree 
Cc: Will Deacon 
Cc: Deng-Cheng Zhu 
Cc: Anton Blanchard 
Cc: Eric B Munson 
Cc: Heiko Carstens 
Cc: Paul Mundt 
Cc: David S. Miller 
Cc: Frederic Weisbecker 
Cc: Jason Wessel 
Cc: Don Zickus 
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar

events: Ensure that timers are updated without requiring read() call

2011-07-01T09:06:34+00:00

The event tracing infrastructure exposes two timers which should be updated
each time the value of the counter is updated.  Currently, these counters are
only updated when userspace calls read() on the fd associated with an event.
This means that counters which are read via the mmap'd page exclusively never
have their timers updated.  This patch adds ensures that the timers are updated
each time the values in the mmap'd page are updated.

Signed-off-by: Eric B Munson 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1308932786-5111-1-git-send-email-emunson@mgebm.net
Signed-off-by: Ingo Molnar

events: Move lockless timer calculation into helper function

2011-07-01T09:06:33+00:00

Take the timer calculation from perf_output_read and move it to a helper
function for any place that needs timer values but cannot take the ctx->lock.

Signed-off-by: Eric B Munson 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1308861279-15216-2-git-send-email-emunson@mgebm.net
Signed-off-by: Ingo Molnar

events: Add note to update_event_times comment about holding ctx->lock

2011-07-01T09:06:33+00:00

Signed-off-by: Eric B Munson 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1308861279-15216-1-git-send-email-emunson@mgebm.net
Signed-off-by: Ingo Molnar

perf_events: Fix perf buffer watermark setting

2011-07-01T09:06:32+00:00

Since 2.6.36 (specifically commit d57e34fdd60b ("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 
Signed-off-by: Peter Zijlstra 
Cc: 
Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106011506390.5384@cl320.eecs.utk.edu
Signed-off-by: Ingo Molnar

perf: Split up buffer handling from core code

2011-06-09T10:57:54+00:00

And create the internal perf events header.

v2: Keep an internal inlined perf_output_copy()

Signed-off-by: Frederic Weisbecker 
Acked-by: Peter Zijlstra 
Cc: Borislav Petkov 
Cc: Stephane Eranian 
Cc: Arnaldo Carvalho de Melo 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/1305827704-5607-1-git-send-email-fweisbec@gmail.com
[ v3: use clearer 'ring_buffer' and 'rb' naming ]
Signed-off-by: Ingo Molnar