Commit 84348fff authored by James Clark's avatar James Clark Committed by Zhong Jinghua
Browse files

perf cs-etm: Remove duplicate and incorrect aux size checks

mainline inclusion
from mainline-v5.16-rc5
commit 7cc9680c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I636PS
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7cc9680c4be7c1da7a3570711f01273b781b936b



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There are two checks, one is for size when running without admin, but
this one is covered by the driver and reported on in more detail here
(builtin-record.c):

  pr_err("Permission error mapping pages.\n"
         "Consider increasing "
         "/proc/sys/kernel/perf_event_mlock_kb,\n"
         "or try again with a smaller value of -m/--mmap_pages.\n"
         "(current value: %u,%u)\n",

This had the effect of artificially limiting the aux buffer size to a
value smaller than what was allowed because perf_event_mlock_kb wasn't
taken into account.

The second is to check for a power of two, but this is covered here
(evlist.c):

  pr_info("rounding mmap pages size to %s (%lu pages)\n",
          buf, pages);

Reviewed-by: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarJames Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211208115435.610101-1-james.clark@arm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarJunhao He <hejunhao3@huawei.com>
parent e4cf0d62
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