[PATCH 04/16] perf mem: Clarify load-latency in documentation

From: Arnaldo Carvalho de Melo
Date: Fri Mar 14 2014 - 17:38:05 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1393596135-4227-2-git-send-email-andi@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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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