From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD11B217659; Fri, 20 Dec 2024 15:30:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734708648; cv=none; b=enmXabPE6cM8+/0BmgmT+suPJsyW3uxne8IBPOBBPYpblV2Vd49JvXF7SibRv9fkYEcyAZc0EKQKc7hWDwjIx4XXnSrj7aorfdiMnTEUfxmA2kMyAGxvegw9Ei8+k1CrC8gHnUBes1F0mzO2FrE8cWb+JZtK7QM9gsVZQPncVFI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734708648; c=relaxed/simple; bh=tdDD6UCXH5j1bsOuSIvYvaOgRIaBkb4exCJWI38jVCE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nn5AmnT4aMnoRTqgcNGA1jBryK296taaKypDg1HgHWTK8XodflJIsdWCP37woGEimSqYXrKEM6VdFQnHlJof3gYHkfFZ2Ko/wiYwwKDfc9lnTxRLlYtnwLCvIf2TmKkUxPdW4uLQowZcSzec60VUXeuUk2tFPxfEtxTXewOKQSc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=A3tqoy7l; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="A3tqoy7l" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=AGI8O9Sne2Jz6QxzLbOPT6Y+rSbNOVcddC2jFEA6Prc=; b=A3tqoy7lxJmhnWCFP13nXsNi0P LCYvFXYDV2UKAEEkj2EGtBnorqQO+GuocHaESgXiSy9YHAhLfqL0J4XNbs9/svNLQ6/nvRWMehc4q 69rmjg3RszdGLLLuXtMrdwNK27aQS40GD3MCr4wXef7TyYng+Gp9m0GMwYGEztnvtXjn/JUBUWTr1 x2g1vvVMUMpmpdm57vOjKbKN8opovmk7AKmJ2CExH3Eno7rhj/1jwMQp/WGxWX4F6hk+rc0hTlAft b77Twf98pCfzTaLc5cVP5t9NxMCfxoVpEAVqrFsotxkggNCNxDT6FMuQsm5Z39V9Hrh9SHMusucgs xAe5cyCA==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tOexd-00000001NXa-0dS3; Fri, 20 Dec 2024 15:30:41 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id E9F643003FF; Fri, 20 Dec 2024 16:30:40 +0100 (CET) Date: Fri, 20 Dec 2024 16:30:40 +0100 From: Peter Zijlstra To: Yeoreum Yun Cc: mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] events/core: fix acoount failure for event's total_enable_time Message-ID: <20241220153040.GP11133@noisy.programming.kicks-ass.net> References: <20241220100202.804062-1-yeoreum.yun@arm.com> <20241220133359.GC17537@noisy.programming.kicks-ass.net> <20241220151414.GO11133@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Dec 20, 2024 at 03:26:42PM +0000, Yeoreum Yun wrote: > > OK, how's this then? > > > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index 065f9188b44a..d12b402f9751 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -2422,6 +2422,7 @@ __perf_remove_from_context(struct perf_event *event, > > { > > struct perf_event_pmu_context *pmu_ctx = event->pmu_ctx; > > unsigned long flags = (unsigned long)info; > > + enum perf_event_state state = PERF_EVENT_STATE_OFF; > > > > ctx_time_update(cpuctx, ctx); > > > > @@ -2438,7 +2439,9 @@ __perf_remove_from_context(struct perf_event *event, > > perf_child_detach(event); > > list_del_event(event, ctx); > > if (flags & DETACH_DEAD) > > - event->state = PERF_EVENT_STATE_DEAD; > > + state = PERF_EVENT_STATE_DEAD; > > + > > + perf_event_set_state(event, state); > > > > It works. but what about this? > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 065f9188b44a..71ed8f847b04 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -2432,6 +2432,7 @@ __perf_remove_from_context(struct perf_event *event, > if (flags & DETACH_DEAD) > event->pending_disable = 1; > event_sched_out(event, ctx); > + perf_event_update_time(event); > if (flags & DETACH_GROUP) > perf_group_detach(event); > if (flags & DETACH_CHILD) Well, the rule is that timekeeping is tied to state change. And as you can see __perf_remove_from_context() violates that. Probably because someone (probably me) figured that the event would not be observed again after detach or something like that.