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| author | Alexey Budankov <alexey.budankov@linux.intel.com> | 2018-11-06 12:04:58 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-12-17 14:55:08 -0300 |
| commit | d3d1af6f011a553a00d2bda90b2700c0d56bd8f7 (patch) | |
| tree | 8f3deb8dcd8b095b3e876fee7d5825c851b10c1c /tools/perf/Documentation | |
| parent | 0b77383134f3dbb461189a9c4f3b46b20152045d (diff) | |
| download | linux-0-day-d3d1af6f011a553a00d2bda90b2700c0d56bd8f7.tar.gz linux-0-day-d3d1af6f011a553a00d2bda90b2700c0d56bd8f7.tar.xz | |
perf record: Enable asynchronous trace writing
The trace file offset is read once before mmaps iterating loop and
written back after all performance data is enqueued for aio writing.
The trace file offset is incremented linearly after every successful aio
write operation.
record__aio_sync() blocks till completion of the started AIO operation
and then proceeds.
record__aio_mmap_read_sync() implements a barrier for all incomplete
aio write requests.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ce2d45e9-d236-871c-7c8f-1bed2d37e8ac@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 246dee081efda..7efb4af88a689 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -435,6 +435,11 @@ Specify vmlinux path which has debuginfo. --buildid-all:: Record build-id of all DSOs regardless whether it's actually hit or not. +--aio:: +Enable asynchronous (Posix AIO) trace writing mode. +Asynchronous mode is supported only when linking Perf tool with libc library +providing implementation for Posix AIO API. + --all-kernel:: Configure all used events to run in kernel space. |