From a3a8ea221c9674f6a30b75aee373c95c0556d769 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 28 Jul 2011 11:05:06 -0400 Subject: [PATCH] Update readme: discuss perf counters Signed-off-by: Mathieu Desnoyers --- README | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/README b/README index 583d0e02..1a7cea16 100644 --- a/README +++ b/README @@ -46,3 +46,10 @@ Support for LTTng 0.x clocks will be added back soon into LTTng 2.0. Please note that lttng-modules 2.0 can build on a Linux kernel patched with the LTTng 0.x patchset, but the lttng-modules 2.0 replace the lttng-modules 0.x, so both tracers cannot be installed at the same time for a given kernel version. + +* Note about Perf PMU counters support + +Each PMU counter has its zero value set when it is attached to a context with +add-context. Therefore, it is normal that the same counters attached to both the +stream context and event context show different values for a given event; what +matters is that they increment at the same rate. -- 2.34.1