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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 760E2C433EF for ; Thu, 7 Oct 2021 10:25:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E09960C4C for ; Thu, 7 Oct 2021 10:25:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234014AbhJGK1J (ORCPT ); Thu, 7 Oct 2021 06:27:09 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:51684 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231825AbhJGK1H (ORCPT ); Thu, 7 Oct 2021 06:27:07 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 9B953203D3; Thu, 7 Oct 2021 10:25:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1633602312; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=bMl2vQKXM/x6+ceqE26rgp1TKwW1WRTeZYtaGsc2hrY=; b=hqOu0yU1oXHTKegGNlAhsyW7kjAeVNIy7PZ/g4Ekb5dTYlVdXKDw8xT21FXob6uFeNicPb COdYkpKvoGPIs3dejZJjkYCpPNk+L/xLjW/CDVK8PujNrl2bd0inZYBc6Cj7fZj9Q5Lzdt iRZ3tsMcT9JjDZF8CtO5Do2bxI+laeo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1633602312; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=bMl2vQKXM/x6+ceqE26rgp1TKwW1WRTeZYtaGsc2hrY=; b=ClbAVRlaFzDs+umFnUwJ3dhDtrCFq18qtFZTKc6tQuWvrK2YGiifo0QqJdwkQBlCa0ZFWZ 2g608Kv3BAbh5gDg== Received: from suse.de (unknown [10.163.43.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 3F2EAA3B83; Thu, 7 Oct 2021 10:25:12 +0000 (UTC) Date: Thu, 7 Oct 2021 11:25:10 +0100 From: Mel Gorman To: Bharata B Rao Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org Subject: Re: [RFC PATCH 4/4] sched/numa: Don't update mm->numa_next_scan from fault path Message-ID: <20211007102510.GQ3891@suse.de> References: <20211004105706.3669-1-bharata@amd.com> <20211004105706.3669-5-bharata@amd.com> <20211005082335.GN3891@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 05, 2021 at 02:40:15PM +0530, Bharata B Rao wrote: > > > > Updating via cmpxchg would be ok to avoid potential collisions between > > threads updating a shared mm. > > Ok, may be I could just resend with changing the scan period update > to use cmpxchg. > > I also notice that in this case of scan period update, we just return > without resetting the p->numa_faults_locality[]. Do you think if > skipping the reset doesn't matter in this case? > If there is no fault activity or migrations are failing, there is no advantage to clearing numa_faults_locality[]. The information there is still useful even if the scan period is updated. -- Mel Gorman SUSE Labs