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 8D6D3C433EF for ; Wed, 15 Jun 2022 01:30:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240711AbiFOBaB (ORCPT ); Tue, 14 Jun 2022 21:30:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229908AbiFOBaA (ORCPT ); Tue, 14 Jun 2022 21:30:00 -0400 Received: from out1.migadu.com (out1.migadu.com [IPv6:2001:41d0:2:863f::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D796A2FFDD; Tue, 14 Jun 2022 18:29:58 -0700 (PDT) MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1655256596; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lY2dF29RfMCDJraWHniXeH1mqvCo+dEuz2ZfjUE/Dcg=; b=MXK61xNGGQMAFxUfmB3NYrHxRlNudq9bfJtI9vOj/CkKRvBdsNSpALpFiNLhqtm2qOl45X Y0U9PKV/5pakKkgGRKJm5LVsZbXpDqk9PpOpJ0fZZST/ROKr0sBM4EqFW9tsXi7BLhiXYM ftUDHugZqh5L+QM5Zsk747Y00bgLBPU= Date: Wed, 15 Jun 2022 01:29:55 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Yajun Deng" Message-ID: Subject: Re: [PATCH] perf/core: fix perf_event_mux_interval_ms when set zero To: "Namhyung Kim" Cc: "Peter Zijlstra" , "Ingo Molnar" , "Arnaldo Carvalho de Melo" , "Mark Rutland" , "Alexander Shishkin" , "Jiri Olsa" , "Stephane Eranian" , "linux-perf-users" , "linux-kernel" In-Reply-To: References: <20220614103751.1395645-1-yajun.deng@linux.dev> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org June 15, 2022 6:08 AM, "Namhyung Kim" wrote:=0A=0A>= Hello,=0A> =0A> On Tue, Jun 14, 2022 at 3:38 AM Yajun Deng wrote:=0A> =0A>> The perf_event_mux_interval_ms is set to zero = or one by default.=0A> =0A> I see that __perf_mux_hrtimer_init() sets it = to PERF_CPU_HRTIMER=0A> if it's less than 1.=0A> =0AYes, pmu->hrtimer_int= erval_ms was set to PERF_CPU_HRTIMER, but perf_event_mux_interval_ms didn= 't.=0AWe can execute 'cat /sys/devices/intel_pt/perf_event_mux_interval_m= s' see that.=0A=0A> Thanks,=0A> Namhyung=0A> =0A>> It can't change back w= hen someone changes it from zero to another=0A>> value.=0A>> =0A>> Make p= erf_event_mux_interval_ms to PERF_CPU_HRTIMER when set zero.=0A>> =0A>> F= ixes: 62b856397927 ("perf: Add sysfs entry to adjust multiplexing interva= l per PMU")=0A>> Signed-off-by: Yajun Deng =0A>> --= -=0A>> kernel/events/core.c | 5 ++++-=0A>> 1 file changed, 4 insertions(+= ), 1 deletion(-)=0A>> =0A>> diff --git a/kernel/events/core.c b/kernel/ev= ents/core.c=0A>> index 61ad10862c21..73c8c7462bbf 100644=0A>> --- a/kerne= l/events/core.c=0A>> +++ b/kernel/events/core.c=0A>> @@ -10954,9 +10954,1= 2 @@ perf_event_mux_interval_ms_store(struct device *dev,=0A>> if (ret)= =0A>> return ret;=0A>> =0A>> - if (timer < 1)=0A>> + if (timer < 0)=0A>> = return -EINVAL;=0A>> =0A>> + if (timer < 1)=0A>> + timer =3D PERF_CPU_HRT= IMER;=0A>> +=0A>> /* same value, noting to do */=0A>> if (timer =3D=3D pm= u->hrtimer_interval_ms)=0A>> return count;=0A>> --=0A>> 2.25.1