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 9EE6AC4332F for ; Wed, 1 Nov 2023 08:58:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234197AbjKAI6Z (ORCPT ); Wed, 1 Nov 2023 04:58:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231570AbjKAI6X (ORCPT ); Wed, 1 Nov 2023 04:58:23 -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 88BB3DE for ; Wed, 1 Nov 2023 01:58:17 -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=p+Hzf1G4MrQChfuvGHTFD7yyXXUPbhrvdydTfbMgYsY=; b=n8+lcZVbqnccHQSYMIXt6GJgEl +M5EwPkhPp1sbxGoAoHY1ozQMT/mCr/QW+D8gQBXxDjV5XIjy9CRE0RQHbPyINAnTGf+5dkr1/f4w NojNQ0aIwCp2vMncdvu3mUaqWDdQF35JvDPJadMbffEjvNKArROF3fdDohs4bHZh/+BGcHobNC460 9ZiQc48j1zkae3tyAOnimJ1lehWpMAIHltbztrbqTI6/9CPkzd4DfixpB9AluKyx+DUFh2Vc5ZIQT tgrmBKnM7oq1fmNqYiLRuQ3lr+xOm/SZ39QKgwE/x+nVXuV5M10hbxB/YDBM+v4EfH73ROA4EH71e qsFUAFog==; 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 1qy733-005bGH-3C; Wed, 01 Nov 2023 08:58:02 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 99E553002AF; Wed, 1 Nov 2023 09:58:01 +0100 (CET) Date: Wed, 1 Nov 2023 09:58:01 +0100 From: Peter Zijlstra To: Peng Liang Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com Subject: Re: [PATCH] sched/fair: remove 2 early returns Message-ID: <20231101085801.GI15024@noisy.programming.kicks-ass.net> References: <20231026123721.957154-1-tcx4c70@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231026123721.957154-1-tcx4c70@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 26, 2023 at 08:37:20PM +0800, Peng Liang wrote: > After commit 5e963f2bd465 ("sched/fair: Commit to EEVDF"), the 2 early > returns in entity_tick can be removed safely. Right, so I still need to go through the whole hrtick thing. I suspect there's more to clean up / fix. For exapmle, I don't think hrtick_update() still makes sense. As to the patch at hand, since slices are now fully controlled through update_curr() -> update_deadline(), I suspect we can clear out more. OTOH, we have the problem where rq-clock and wall-time are not running at the same rate, so hrtick might come in early, so that's something to look into. So I don't mind this patch per-se, but I do think there's far more work to be done here.