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 D6FF5C7619A for ; Wed, 12 Apr 2023 14:26:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230033AbjDLO0d (ORCPT ); Wed, 12 Apr 2023 10:26:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229679AbjDLO0b (ORCPT ); Wed, 12 Apr 2023 10:26:31 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0376170A for ; Wed, 12 Apr 2023 07:26:27 -0700 (PDT) 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=3qJvIOxoolczQy5RdZ6v4DRFskdaG0Va0CAKh9b55/o=; b=PDT7uMS3oxgyC5Wp+jDvcYXhzD gHJUi3Ti9E8JrYvOSvhFdTp02iqhf5Rlcc4qafPBkkFk3d/+D3YNUtl2WB5WmPXOedVLAXuA4YjMA 4pSZ5JoWJrYgLE74Gure9MnC26pJaM7NU1ddPjIymgF4GxrgURfmb/og9PybSTz/8rXUink/GC3uS hOsOHfVJSFSARsAD16GcLIMpq+VOaf2ywkKDMj33R9/vMcytNloxOSeXHOp4cXr3uJypVdxqBYel8 RDNg3IVgFgiCdONa60RrkkhPBVaErTF2QwQpb63FzXY+weH/juUcvikSeaQuuRE38J9vHw91G5I6J EL5J4n3w==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pmbQP-00DwfQ-2j; Wed, 12 Apr 2023 14:26:18 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B3462300274; Wed, 12 Apr 2023 16:26:16 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9A8E921239575; Wed, 12 Apr 2023 16:26:16 +0200 (CEST) Date: Wed, 12 Apr 2023 16:26:16 +0200 From: Peter Zijlstra To: Aaron Lu Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, Olivier Dion , michael.christie@oracle.com Subject: Re: [RFC PATCH v4] sched: Fix performance regression introduced by mm_cid Message-ID: <20230412142616.GI628377@hirez.programming.kicks-ass.net> References: <20230410150150.2179062-1-mathieu.desnoyers@efficios.com> <20230411045225.GA3509@ziqianlu-desk2> <20230411131221.GA7356@ziqianlu-desk2> <20230412091043.GC4253@hirez.programming.kicks-ass.net> <20230412114240.GA155547@ziqianlu-desk2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230412114240.GA155547@ziqianlu-desk2> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 12, 2023 at 07:42:40PM +0800, Aaron Lu wrote: > I *guess* you might be able to see some contention with hackbench on > that HSW-EX system with v4. Indeed! Notably it seems to be the wakeup from idle that trips it hardest: 11.31% 0.03% swapper [kernel.vmlinux] [k] schedule_idle | --11.28%--schedule_idle | --11.27%--__schedule | |--8.61%--mm_cid_get | | | --5.78%--_raw_spin_lock | | | --5.56%--native_queued_spin_lock_slowpath | |--0.81%--finish_task_switch.isra.0 | | | --0.69%--asm_sysvec_call_function_single | | | --0.58%--sysvec_call_function_single | --0.57%--switch_mm_irqs_off