linux/include
Peter Zijlstra 7f453c24b9 perf_counter: PERF_SAMPLE_ID and inherited counters
Anton noted that for inherited counters the counter-id as provided by
PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID
because each inherited counter gets its own id.

His suggestion was to always return the parent counter id, since that
is the primary counter id as exposed. However, these inherited
counters have a unique identifier so that events like
PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which
counter gets modified, which is important when trying to normalize the
sample streams.

This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD,
which is more useful anyway, since changing periods became a lot more
common than initially thought -- rendering PERF_EVENT_PERIOD the less
useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate
value, since it reports the value used to trigger the overflow,
whereas PERF_EVENT_PERIOD simply reports the requested period changed,
which might only take effect on the next cycle).

This still leaves us PERF_EVENT_THROTTLE to consider, but since that
_should_ be a rare occurrence, and linking it to a primary id is the
most useful bit to diagnose the problem, we introduce a
PERF_SAMPLE_STREAM_ID, for those few cases where the full
reconstruction is important.

[Does change the ABI a little, but I see no other way out]

Suggested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248095846.15751.8781.camel@twins>
2009-07-22 18:05:56 +02:00
..
acpi Merge branch 'bjorn-notify' into release 2009-06-24 01:22:20 -04:00
asm-generic alpha: fix percpu build breakage 2009-06-30 18:55:59 -07:00
crypto
drm drm: Fix shifts which were miscalculated when converting from bitfields. 2009-06-24 16:11:04 +10:00
keys
linux perf_counter: PERF_SAMPLE_ID and inherited counters 2009-07-22 18:05:56 +02:00
math-emu
media V4L/DVB (11901): v4l2: Create helper function for bounding and aligning images 2009-06-23 03:21:18 -03:00
mtd Kill jffs2-user.h 2009-06-05 17:31:38 +01:00
net Phonet: publicize the Netlink notification function 2009-06-25 02:58:15 -07:00
pcmcia
rdma
rxrpc
scsi sd, sr: fix Driver 'sd' needs updating message 2009-06-21 12:01:27 -05:00
sound Merge branch 'topic/pcm-jiffies-check' into for-linus 2009-06-10 07:26:41 +02:00
trace ext4: convert instrumentation from markers to tracepoints 2009-06-17 11:48:11 -04:00
video fbdev: s1d13xxxfb: add accelerated bitblt functions 2009-06-16 19:48:00 -07:00
xen
Kbuild [SCSI] FC Pass Thru support 2009-06-12 14:20:05 -05:00