Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753808Ab0KWNTd (ORCPT ); Tue, 23 Nov 2010 08:19:33 -0500 Received: from mail-wy0-f174.google.com ([74.125.82.174]:40901 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998Ab0KWNTc (ORCPT ); Tue, 23 Nov 2010 08:19:32 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version:content-type; b=qqZyT5GUpd3klaVuhRxVVIoDhGauz/ukOJLfECGHbQjdZsp2YglIm0hh552P8UYcU/ dbZaRQyMID2H/1ql0SPenCdF4KiNxkBVYZfn6lxwJn6gh0uOkRgcNkfSuFzKVhXMNqqX rfDLlfc5gbZ6gKLgbCvmRboQ38xrFTtCBS/e0= From: Franck Bui-Huu To: Peter Zijlstra Cc: Franck Bui-Huu , lkml Subject: Re: How about limiting refresh ioctl to sampling events ? References: <1290517646.2072.403.camel@laptop> Date: Tue, 23 Nov 2010 14:19:25 +0100 In-Reply-To: <1290517646.2072.403.camel@laptop> (Peter Zijlstra's message of "Tue, 23 Nov 2010 14:07:26 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1319 Lines: 46 Peter Zijlstra writes: > On Tue, 2010-11-23 at 14:01 +0100, Franck Bui-Huu wrote: >> Hello Peter, >> >> I'm looking at the perf event stuff and wondering if > >> perf_event_refresh() should be limited to sampling events. >> >> Does the following make sense ? >> >> diff --git a/kernel/perf_event.c b/kernel/perf_event.c >> index 3b105e0..1a90a6c 100644 >> --- a/kernel/perf_event.c >> +++ b/kernel/perf_event.c >> @@ -1072,7 +1072,7 @@ static int perf_event_refresh(struct perf_event *event, int refresh) >> /* >> * not supported on inherited events >> */ >> - if (event->attr.inherit) >> + if (event->attr.inherit || !event->attr.sample_period) >> return -EINVAL; >> >> atomic_add(refresh, &event->event_limit); > > Yes it does, please submit as a proper patch. Ok. I'm also wondering if you would accept a second patch which will introduce: static inline bool is_sampling_event(struct perf_event *event) { return event->attr.sample_period != 0; } That would make the code slighlty easier to read IMHO. -- Franck -- 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/