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author | Peter Zijlstra <peterz@infradead.org> | 2015-01-23 13:19:48 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-08 08:44:10 +0300 |
commit | 5a7b3b1ec16b6bfa57752d37292988e64fcdd172 (patch) | |
tree | 2759c94f1bc0ff3d489af2b113035c4de88d6950 /include/linux/posix_acl.h | |
parent | 42f268023df2919f484d8b46df34b35323bd3358 (diff) | |
download | linux-5a7b3b1ec16b6bfa57752d37292988e64fcdd172.tar.xz |
perf: Tighten (and fix) the grouping condition
commit c3c87e770458aa004bd7ed3f29945ff436fd6511 upstream.
The fix from 9fc81d87420d ("perf: Fix events installation during
moving group") was incomplete in that it failed to recognise that
creating a group with events for different CPUs is semantically
broken -- they cannot be co-scheduled.
Furthermore, it leads to real breakage where, when we create an event
for CPU Y and then migrate it to form a group on CPU X, the code gets
confused where the counter is programmed -- triggered in practice
as well by me via the perf fuzzer.
Fix this by tightening the rules for creating groups. Only allow
grouping of counters that can be co-scheduled in the same context.
This means for the same task and/or the same cpu.
Fixes: 9fc81d87420d ("perf: Fix events installation during moving group")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/posix_acl.h')
0 files changed, 0 insertions, 0 deletions