lkml.org 
[lkml]   [2009]   [Jun]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] perf_counters: start documenting HAVE_PERF_COUNTERS requirements
Date
Help out arch porters who want to support perf counters by listing some
basic requirements.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
i imagine more details would be good, but this is a starting point and
better than nothing
init/Kconfig | 2 ++
tools/perf/design.txt | 15 +++++++++++++++
2 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/init/Kconfig b/init/Kconfig
index c649657..20f85b1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -936,6 +936,8 @@ config AIO

config HAVE_PERF_COUNTERS
bool
+ help
+ See end of tools/perf/design.txt

menu "Performance Counters"

diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index 860e116..f71e0d2 100644
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -440,3 +440,18 @@ by this process or by another, and doesn't affect any counters that
this process has created on other processes. It only enables or
disables the group leaders, not any other members in the groups.

+
+Arch requirements
+-----------------
+
+If your architecture does not have hardware performance metrics, you can
+still use the generic software counters based on hrtimers for sampling.
+
+So to start with, in order to add HAVE_PERF_COUNTERS to your Kconfig, you
+will need at least this:
+ - asm/perf_counter.h - a basic stub will suffice at first
+ - support for atomic64 types (and associated helper functions)
+ - set_perf_counter_pending() implemented
+
+If your architecture does have hardware capabilities, you can override the
+weak stub hw_perf_counter_init() to register hardware counters.
--
1.6.3.1


\
 
 \ /
  Last update: 2009-06-12 19:21    [from the cache]
©2003-2011 Jasper Spaans