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authorAndi Kleen <ak@linux.intel.com>2014-02-28 06:02:14 -0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-03-14 11:20:44 -0300
commitb63940970492f5f187d546e191bc2c6831491fe3 (patch)
tree7cb6844706b7bcb238ccbad8fb311a27803836c8 /tools/perf/Documentation
parent0fb298cf95c0d8119557b7d4657724a146e0622e (diff)
downloadop-kernel-dev-b63940970492f5f187d546e191bc2c6831491fe3.zip
op-kernel-dev-b63940970492f5f187d546e191bc2c6831491fe3.tar.gz
perf mem: Clarify load-latency in documentation
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>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-mem.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
index 888d511..1d78a40 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
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<command>...::
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