Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 04/16] perf mem: Clarify load-latency in documentation | Date | Fri, 14 Mar 2014 18:29:58 -0300 |
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From: Andi Kleen <ak@linux.intel.com>
Clarify in the documentation that 'perf mem report' reports use-latency, not load/store-latency on Intel systems.
This often causes confusion with users.
Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1393596135-4227-2-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/Documentation/perf-mem.txt | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt index 888d51137fbe..1d78a4064da4 100644 --- a/tools/perf/Documentation/perf-mem.txt +++ b/tools/perf/Documentation/perf-mem.txt @@ -18,6 +18,10 @@ from it, into perf.data. Perf record options are accepted and are passed through "perf mem -t <TYPE> report" displays the result. It invokes perf report with the right set of options to display a memory access profile. +Note that on Intel systems the memory latency reported is the use-latency, +not the pure load (or store latency). Use latency includes any pipeline +queueing delays in addition to the memory subsystem latency. + OPTIONS ------- <command>...:: -- 1.8.1.4
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