From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 02EB827A47C for ; Tue, 20 May 2025 19:38:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747769924; cv=none; b=d2g8wmvHaUrQYhVQPK9y7H4xQ85ZNcvsUC/to1ptt2COBEDqK0HVpk+hjfDZWjhtiJNS34Y2nLMVBtRAE0ENcOgVJ9XZrDNPSz+7aIWn55Gj5tfbdylSmR5YwlG/hmbKc7Poe0wNICUpM3+vFhuVxtGBfxX0GN1KG0tchZwdaEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747769924; c=relaxed/simple; bh=TDij//lCWY7he7Ok3rLRBwXncLSPSWE83xM6Zo8Eq4w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Qj0pXXg2Z019gIa9EsAchmGqxHUR0Xb8BbxzPDjNYym1bRP3WDcsT7BCI6aDlvY625+NMDkH7p9rx2JLaytGN8suQyqZdNgN9B5FNga0r7ZyFr/CVF9+4U7faJ4H5OfCqe6Gxmggd2lRI7nfb4FUO00CmuDeCxgtPDs2UvCf+CU= 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=XM6I19vV; arc=none smtp.client-ip=90.155.92.199 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="XM6I19vV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=bCTU4ad3V8gf9noWeHBCwci+jkHN3102qasXnqo/LKE=; b=XM6I19vVSq45VjrZPfye042zqj lz/RllRY4BMGS9bBYZRpTEFeLadUXBw1EGUd7CDbdCGuge6T3cdCfQA/InX8zxQ0/2Dkknpgslqcn BYCBxVrlYON18cMyaCzSxk3DT43jrQvOVLrsmN7K0UkB6B8ttosC65upz6e/xWhcckNEOGXtT240t 4bepFSxALRd4Gjbt31MzVtqQFkp5Kf2ErTgT3LmxmbmdSVJmPfesObHgmkwofxpaot3cVj0l7AmY3 6T3YRu5u4BniRX4/l3dQnNfm1wkYm1ua6jBxha8/TWt/YJ20zfbWut97wCD8dkMPrqFhaYCgTNX0i JcD5k6sA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.1 #2 (Red Hat Linux)) id 1uHSnI-00000000oAD-01uX; Tue, 20 May 2025 19:38:35 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 7A8DA300677; Tue, 20 May 2025 21:38:31 +0200 (CEST) Date: Tue, 20 May 2025 21:38:31 +0200 From: Peter Zijlstra To: Dietmar Eggemann Cc: Chris Mason , linux-kernel@vger.kernel.org, Ingo Molnar , vschneid@redhat.com, Juri Lelli , Thomas Gleixner Subject: Re: scheduler performance regression since v6.11 Message-ID: <20250520193831.GB39944@noisy.programming.kicks-ass.net> References: <1e3c711f-8c96-4c39-bbe2-7742940d1d31@meta.com> <20250509194955.GA25798@noisy.programming.kicks-ass.net> <20250512180846.GA25891@noisy.programming.kicks-ass.net> <2f394a01-1cd9-4719-9394-647d8731cf3f@meta.com> <20250516101822.GC16434@noisy.programming.kicks-ass.net> <2084b7d9-bb4f-4a5e-aaec-98e07b3edc2e@arm.com> 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: <2084b7d9-bb4f-4a5e-aaec-98e07b3edc2e@arm.com> On Tue, May 20, 2025 at 04:38:09PM +0200, Dietmar Eggemann wrote: > 3840cbe24cf0 - sched: psi: fix bogus pressure spikes from aggregation race > > With CONFIG_PSI enabled we call cpu_clock(cpu) now multiple times (up to > 4 times per task switch in my setup) in: > > __schedule() -> psi_sched_switch() -> psi_task_switch() -> > psi_group_change(). > > There seems to be another/other v6.12 related patch(es) later which > cause(s) another 4% regression I yet have to discover. Urgh, let me add this to the pile to look at. Thanks!