Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764933AbZFLRkT (ORCPT ); Fri, 12 Jun 2009 13:40:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755234AbZFLRkG (ORCPT ); Fri, 12 Jun 2009 13:40:06 -0400 Received: from hera.kernel.org ([140.211.167.34]:34251 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754476AbZFLRkF (ORCPT ); Fri, 12 Jun 2009 13:40:05 -0400 Date: Fri, 12 Jun 2009 17:39:29 GMT From: tip-bot for Mike Frysinger To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, vapier@gentoo.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, vapier@gentoo.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1244827063-24046-1-git-send-email-vapier@gentoo.org> References: <1244827063-24046-1-git-send-email-vapier@gentoo.org> Subject: [tip:perfcounters/core] perf_counter: Start documenting HAVE_PERF_COUNTERS requirements Message-ID: Git-Commit-ID: 018df72dd01576ab199c6129233cdeaf1409958b X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 12 Jun 2009 17:39:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2323 Lines: 65 Commit-ID: 018df72dd01576ab199c6129233cdeaf1409958b Gitweb: http://git.kernel.org/tip/018df72dd01576ab199c6129233cdeaf1409958b Author: Mike Frysinger AuthorDate: Fri, 12 Jun 2009 13:17:43 -0400 Committer: Ingo Molnar CommitDate: Fri, 12 Jun 2009 19:37:30 +0200 perf_counter: Start documenting HAVE_PERF_COUNTERS requirements Help out arch porters who want to support perf counters by listing some basic requirements. Signed-off-by: Mike Frysinger Cc: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <1244827063-24046-1-git-send-email-vapier@gentoo.org> Signed-off-by: Ingo Molnar --- 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..d3a5096 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -936,6 +936,8 @@ config AIO config HAVE_PERF_COUNTERS bool + help + See tools/perf/design.txt for details. 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/