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 19041C4332F for ; Thu, 24 Nov 2022 05:29:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229532AbiKXF27 (ORCPT ); Thu, 24 Nov 2022 00:28:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229450AbiKXF25 (ORCPT ); Thu, 24 Nov 2022 00:28:57 -0500 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FF39C052C; Wed, 23 Nov 2022 21:28:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669267736; x=1700803736; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=yzllx2aXHanc4RlM697MHQ9doyide2+HpLsBlPh6fPY=; b=a7dd0UFqA3/b8+LxYo0ChDAgo7WfRQGqC1iCpvwDfDhxowOyxepWaw59 apO8di9w/hQ9DO5tyKbiukx/RD58d+9ULQ2jxwo8wCBoeL/o76M4lqglR kBjEX7DKXNZdWdOiB5k07/fu6jm6VMbne4/S5R6Hf9voHISOupa1ZgfDR M2IInhX9pJAR2UDZ+HL/29V9P4HE8VjSq3PtrnHKoTW7BZEsRtq1hes5l u8QABUokbJdktH0woThF8vlEusrI1zMxyCJxP1gplu4bJIL7Z63Yf/BFe vsKz75MvKFdxLlqkiIX3FVlZRGQg0cPTptorCBnyo18l/j8+YbRVbTvxS Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10540"; a="316039962" X-IronPort-AV: E=Sophos;i="5.96,189,1665471600"; d="scan'208";a="316039962" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2022 21:28:56 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10540"; a="887219634" X-IronPort-AV: E=Sophos;i="5.96,189,1665471600"; d="scan'208";a="887219634" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2022 21:28:52 -0800 From: "Huang, Ying" To: Mina Almasry Cc: Yang Shi , Yosry Ahmed , Tim Chen , weixugc@google.com, shakeelb@google.com, gthelen@google.com, fvdl@google.com, Andrew Morton , Muchun Song , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v1 3/4] mm: Fix demotion-only scanning anon pages References: <20221122203850.2765015-1-almasrymina@google.com> <20221122203850.2765015-3-almasrymina@google.com> Date: Thu, 24 Nov 2022 13:27:51 +0800 In-Reply-To: <20221122203850.2765015-3-almasrymina@google.com> (Mina Almasry's message of "Tue, 22 Nov 2022 12:38:47 -0800") Message-ID: <87wn7korag.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mina Almasry writes: > This is likely a missed change from commit a2a36488a61c ("mm/vmscan: Consider > anonymous pages without swap"). Current logic is if !may_swap _or_ > !can_reclaim_anon_pages() then we don't scan anon memory. > > This should be an 'and'. We would like to scan anon memory if we may swap > or if we can_reclaim_anon_pages(). > > Fixes: commit a2a36488a61c ("mm/vmscan: Consider anonymous pages without swap") > > Signed-off-by: Mina Almasry > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 8c1f5416d789..d7e509b3f07f 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2931,7 +2931,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, > enum lru_list lru; > > /* If we have no swap space, do not bother scanning anon folios. */ > - if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { > + if (!sc->may_swap && !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { If there is only DRAM but swap device is enabled, sc->may_swap will not work as expected. So we should check can_demote() instead if sc->may_swap. Best Regards, Huang, Ying > scan_balance = SCAN_FILE; > goto out; > } > -- > 2.38.1.584.g0f3c55d4c2-goog From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Huang, Ying" Subject: Re: [RFC PATCH v1 3/4] mm: Fix demotion-only scanning anon pages Date: Thu, 24 Nov 2022 13:27:51 +0800 Message-ID: <87wn7korag.fsf@yhuang6-desk2.ccr.corp.intel.com> References: <20221122203850.2765015-1-almasrymina@google.com> <20221122203850.2765015-3-almasrymina@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669267736; x=1700803736; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=yzllx2aXHanc4RlM697MHQ9doyide2+HpLsBlPh6fPY=; b=a7dd0UFqA3/b8+LxYo0ChDAgo7WfRQGqC1iCpvwDfDhxowOyxepWaw59 apO8di9w/hQ9DO5tyKbiukx/RD58d+9ULQ2jxwo8wCBoeL/o76M4lqglR kBjEX7DKXNZdWdOiB5k07/fu6jm6VMbne4/S5R6Hf9voHISOupa1ZgfDR M2IInhX9pJAR2UDZ+HL/29V9P4HE8VjSq3PtrnHKoTW7BZEsRtq1hes5l u8QABUokbJdktH0woThF8vlEusrI1zMxyCJxP1gplu4bJIL7Z63Yf/BFe vsKz75MvKFdxLlqkiIX3FVlZRGQg0cPTptorCBnyo18l/j8+YbRVbTvxS Q==; In-Reply-To: <20221122203850.2765015-3-almasrymina-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> (Mina Almasry's message of "Tue, 22 Nov 2022 12:38:47 -0800") List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mina Almasry Cc: Yang Shi , Yosry Ahmed , Tim Chen , weixugc-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, gthelen-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, fvdl-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Andrew Morton , Muchun Song , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org Mina Almasry writes: > This is likely a missed change from commit a2a36488a61c ("mm/vmscan: Consider > anonymous pages without swap"). Current logic is if !may_swap _or_ > !can_reclaim_anon_pages() then we don't scan anon memory. > > This should be an 'and'. We would like to scan anon memory if we may swap > or if we can_reclaim_anon_pages(). > > Fixes: commit a2a36488a61c ("mm/vmscan: Consider anonymous pages without swap") > > Signed-off-by: Mina Almasry > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 8c1f5416d789..d7e509b3f07f 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2931,7 +2931,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, > enum lru_list lru; > > /* If we have no swap space, do not bother scanning anon folios. */ > - if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { > + if (!sc->may_swap && !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { If there is only DRAM but swap device is enabled, sc->may_swap will not work as expected. So we should check can_demote() instead if sc->may_swap. Best Regards, Huang, Ying > scan_balance = SCAN_FILE; > goto out; > } > -- > 2.38.1.584.g0f3c55d4c2-goog