[PATCH V3 0/2] Improvement and fixes for BHRB

Anshuman Khandual khandual at linux.vnet.ibm.com
Mon Jun 10 15:25:08 EST 2013


(1) The first patch fixes a situation like this

Before patch:-
------------

./perf record -j any -e branch-misses:k ls
Error:
The sys_perf_event_open() syscall returned with 95 (Operation not supported) for event (branch-misses:k).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?

Here 'perf record' actually copies over ':k' filter request into BHRB
privilege state filter config and our previous check in kernel would
fail that.

After patch:-
-------------

/perf record -j any -e branch-misses:k ls
perf  perf.data  perf.data.old  test-mmap-ring
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.002 MB perf.data (~102 samples) ]

(2) The second patch fixes context migration for BHRB filter configuration

Changes in V2
-------------
(1) Updated the comment section of the code
(2) Removed the informational print
(3) Updated the commit section of the first patch

Changes in V3
-------------
(1) Fixed the compilation warning problem after removing the unused variable

Anshuman Khandual (2):
  powerpc, perf: Ignore separate BHRB privilege state filter request
  powerpc, perf: BHRB filter configuration should follow the task

 arch/powerpc/perf/core-book3s.c |  5 ++++-
 arch/powerpc/perf/power8-pmu.c  | 13 ++++---------
 2 files changed, 8 insertions(+), 10 deletions(-)

-- 
1.7.11.7



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