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 66DAEC6FD1D for ; Tue, 4 Apr 2023 09:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234147AbjDDJWD (ORCPT ); Tue, 4 Apr 2023 05:22:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234140AbjDDJWA (ORCPT ); Tue, 4 Apr 2023 05:22:00 -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 A97D11981 for ; Tue, 4 Apr 2023 02:21:58 -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=r5aK41JlmJ+wuIMmAeBq19Fz0dTVrVv8FNnEIqiUcs0=; b=pl/uWVk2g8WaNL+TeyByZcKuir 2DhHktRl0GxFg6D/gKiUOa+lBtcN+ihigAqKadwxiR09f1nXVr6oRt3mZGaqo1BvONkvcPAdf6tGs So9RcovZCAfF2R4Y1t3nFMJ6sEtr3DnLSqrg6Hq/D3CewOnF/IBhK/Mo7QDEj8tARvn2vNzje1hsO oew2b1plv8AQOVXAxhM7iP0LstnQ+Uy5uQnx6m7/NdpH3hykhXNFPw9VPdoYX+YmVBT+crgeWeCWH E4pqwkR3vxzrfnNYZ4JXL4+h7SxtbcTZFVbPQnmkrWzf04t1prmj1/LHdZd2IeRrNkhiOYHAbt5oD cmDUX0aQ==; 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 1pjcrN-009DaY-1x; Tue, 04 Apr 2023 09:21:49 +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)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 992A930003A; Tue, 4 Apr 2023 11:21:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7F113242109F9; Tue, 4 Apr 2023 11:21:48 +0200 (CEST) Date: Tue, 4 Apr 2023 11:21:48 +0200 From: Peter Zijlstra To: Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org, Aaron Lu Subject: Re: [RFC PATCH] sched: Fix performance regression introduced by mm_cid Message-ID: <20230404092148.GC284733@hirez.programming.kicks-ass.net> References: <20230403181342.210896-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230403181342.210896-1-mathieu.desnoyers@efficios.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 03, 2023 at 02:13:42PM -0400, Mathieu Desnoyers wrote: > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 0d18c3969f90..775c7da6ec7f 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2326,16 +2326,20 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) > static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, > struct task_struct *p, int new_cpu) > { > + int cid; > + > lockdep_assert_rq_held(rq); > > deactivate_task(rq, p, DEQUEUE_NOCLOCK); > set_task_cpu(p, new_cpu); > + cid = sched_mm_cid_migrate_from(rq, p); > rq_unlock(rq, rf); > > rq = cpu_rq(new_cpu); > > rq_lock(rq, rf); > WARN_ON_ONCE(task_cpu(p) != new_cpu); > + sched_mm_cid_migrate_to(rq, p, cid); > activate_task(rq, p, 0); > check_preempt_curr(rq, p, 0); > I can't find more uses? Yet there are a ton more ways to actually migrate tasks.