From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52A0EC43334 for ; Tue, 14 Jun 2022 22:08:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355936AbiFNWIj (ORCPT ); Tue, 14 Jun 2022 18:08:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358464AbiFNWI1 (ORCPT ); Tue, 14 Jun 2022 18:08:27 -0400 Received: from mail-oa1-f49.google.com (mail-oa1-f49.google.com [209.85.160.49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC3294EDEC; Tue, 14 Jun 2022 15:08:26 -0700 (PDT) Received: by mail-oa1-f49.google.com with SMTP id 586e51a60fabf-fe4ac3b87fso14319370fac.3; Tue, 14 Jun 2022 15:08:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=uL+pfJik+rRQSzc9i4k7KVHHfK2XbB8mJChZyZzr7dg=; b=HYQeEdIOv0BAeqhZeFoYdjszgmt2IE42IC/1gm1qQoCEY/px33MW0QAb/KU5JGAhjt x7rUiUZTJjI+Y/X70uS+Neu/VZyBI7y6DrASxieeGquMu/W7vqWBcR57ANEO4Xlczl2o bYSsA4WNWuQFy6AltI/pVzkjofi4GihqzZbyqPdiQCQxdkHPKBOrgYl+Qj5rcqR467PW 2XZOPcvOQlUjxZDwvSOem6vIvldJOTKsr9A+Ox59QWS/0WoefZfOHGFHQMLKGw+3PURo MJCkXLbduPWIzBOFhv5SzyDoQJSRLWNkLN7bmsOJ4y0zRnqYXZvWCcLypcRa2WYsF1JS u1Fw== X-Gm-Message-State: AJIora9ssO30nTs3rcOHDXIDVR8/YTWwB5deiw1K8FShkLcZTsavfyax JVaVUx1i287DBuFf+VXiM3tvVo6wlxXv5IlG7f0= X-Google-Smtp-Source: AGRyM1uTl5swnr44HgvS3WnCGGSBkcYZyGp2KxlIhOgybf9f+SSY/eyv4iYT3URmqg8eMxOPoSae0XBP+EYvB9ug+Qo= X-Received: by 2002:a05:6870:4585:b0:fb:5105:76b8 with SMTP id y5-20020a056870458500b000fb510576b8mr3555860oao.92.1655244506189; Tue, 14 Jun 2022 15:08:26 -0700 (PDT) MIME-Version: 1.0 References: <20220614103751.1395645-1-yajun.deng@linux.dev> In-Reply-To: <20220614103751.1395645-1-yajun.deng@linux.dev> From: Namhyung Kim Date: Tue, 14 Jun 2022 15:08:15 -0700 Message-ID: Subject: Re: [PATCH] perf/core: fix perf_event_mux_interval_ms when set zero To: Yajun Deng Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Stephane Eranian , linux-perf-users , linux-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Jun 14, 2022 at 3:38 AM Yajun Deng wrote: > > The perf_event_mux_interval_ms is set to zero or one by default. I see that __perf_mux_hrtimer_init() sets it to PERF_CPU_HRTIMER if it's less than 1. Thanks, Namhyung > It can't change back when someone changes it from zero to another > value. > > Make perf_event_mux_interval_ms to PERF_CPU_HRTIMER when set zero. > > Fixes: 62b856397927 ("perf: Add sysfs entry to adjust multiplexing interval per PMU") > Signed-off-by: Yajun Deng > --- > kernel/events/core.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 61ad10862c21..73c8c7462bbf 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -10954,9 +10954,12 @@ perf_event_mux_interval_ms_store(struct device *dev, > if (ret) > return ret; > > - if (timer < 1) > + if (timer < 0) > return -EINVAL; > > + if (timer < 1) > + timer = PERF_CPU_HRTIMER; > + > /* same value, noting to do */ > if (timer == pmu->hrtimer_interval_ms) > return count; > -- > 2.25.1 >