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authorRavi Bangoria <ravi.bangoria@linux.ibm.com>2019-01-29 18:54:12 +0530
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-02-04 11:32:14 -0300
commitf0fabf9c897327abd39018aefb5029aff8c7e133 (patch)
tree7f438664f6584e3acb442a6a12150a468db03869 /tools/perf/Documentation
parent489338a717a0dfbbd5a3fabccf172b78f0ac9015 (diff)
downloadlinux-f0fabf9c897327abd39018aefb5029aff8c7e133.tar.bz2
perf mem/c2c: Fix perf_mem_events to support powerpc
PowerPC hardware does not have a builtin latency filter (--ldlat) for the "mem-load" event and perf_mem_events by default includes "/ldlat=30/" which is causing a failure on PowerPC. Refactor the code to support "perf mem/c2c" on PowerPC. This patch depends on kernel side changes done my Madhavan: https://lists.ozlabs.org/pipermail/linuxppc-dev/2018-December/182596.html Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Dick Fowles <fowles@inreach.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Joe Mario <jmario@redhat.com> Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20190129132412.771-1-ravi.bangoria@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-c2c.txt16
-rw-r--r--tools/perf/Documentation/perf-mem.txt2
2 files changed, 13 insertions, 5 deletions
diff --git a/tools/perf/Documentation/perf-c2c.txt b/tools/perf/Documentation/perf-c2c.txt
index 095aebdc5bb7..e6150f21267d 100644
--- a/tools/perf/Documentation/perf-c2c.txt
+++ b/tools/perf/Documentation/perf-c2c.txt
@@ -19,8 +19,11 @@ C2C stands for Cache To Cache.
The perf c2c tool provides means for Shared Data C2C/HITM analysis. It allows
you to track down the cacheline contentions.
-The tool is based on x86's load latency and precise store facility events
-provided by Intel CPUs. These events provide:
+On x86, the tool is based on load latency and precise store facility events
+provided by Intel CPUs. On PowerPC, the tool uses random instruction sampling
+with thresholding feature.
+
+These events provide:
- memory address of the access
- type of the access (load and store details)
- latency (in cycles) of the load access
@@ -46,7 +49,7 @@ RECORD OPTIONS
-l::
--ldlat::
- Configure mem-loads latency.
+ Configure mem-loads latency. (x86 only)
-k::
--all-kernel::
@@ -119,11 +122,16 @@ Following perf record options are configured by default:
-W,-d,--phys-data,--sample-cpu
Unless specified otherwise with '-e' option, following events are monitored by
-default:
+default on x86:
cpu/mem-loads,ldlat=30/P
cpu/mem-stores/P
+and following on PowerPC:
+
+ cpu/mem-loads/
+ cpu/mem-stores/
+
User can pass any 'perf record' option behind '--' mark, like (to enable
callchains and system wide monitoring):
diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
index f8d2167cf3e7..199ea0f0a6c0 100644
--- a/tools/perf/Documentation/perf-mem.txt
+++ b/tools/perf/Documentation/perf-mem.txt
@@ -82,7 +82,7 @@ RECORD OPTIONS
Be more verbose (show counter open errors, etc)
--ldlat <n>::
- Specify desired latency for loads event.
+ Specify desired latency for loads event. (x86 only)
In addition, for report all perf report options are valid, and for record
all perf record options.