korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-16 00:34:20 +08:00
Code Issues Packages Projects Releases Wiki Activity
313ccb9615
linux/kernel/events
History
Jiri Olsa 313ccb9615 perf: Allocate context task_ctx_data for child event 
Currently we use perf_event_context::task_ctx_data to save and restore
the LBR status when the task is scheduled out and in.

We don't allocate it for child contexts, which results in shorter task's
LBR stack, because we don't save the history from previous run and start
over every time we schedule the task in.

I made a test to generate samples with LBR call stack and got higher
numbers on bigger chain depths:

                            before:     after:
  LBR call chain: nr: 1       60561     498127
  LBR call chain: nr: 2           0          0
  LBR call chain: nr: 3      107030       2172
  LBR call chain: nr: 4      466685      62758
  LBR call chain: nr: 5     2307319     878046
  LBR call chain: nr: 6       48713     495218
  LBR call chain: nr: 7        1040       4551
  LBR call chain: nr: 8         481        172
  LBR call chain: nr: 9         878        120
  LBR call chain: nr: 10       2377       6698
  LBR call chain: nr: 11      28830     151487
  LBR call chain: nr: 12      29347     339867
  LBR call chain: nr: 13          4         22
  LBR call chain: nr: 14          3         53

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 4af57ef28c ("perf: Add pmu specific data for perf task context")
Link: http://lkml.kernel.org/r/20180107160356.28203-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-01-08 12:26:46 -03:00
..
callchain.c perf/callchain: Force USER_DS when invoking perf_callchain_user() 2017-05-10 07:54:00 +02:00
core.c perf: Allocate context task_ctx_data for child event 2018-01-08 12:26:46 -03:00
hw_breakpoint.c perf: Collapse and fix event_function_call() users 2016-01-21 18:54:24 +01:00
internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ring_buffer.c arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
uprobes.c mm, uprobes: fix multiple free of ->uprobes_state.xol_area 2017-08-31 16:33:15 -07:00