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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1BF0C3DA7D for ; Tue, 3 Jan 2023 07:35:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6E3F18E0002; Tue, 3 Jan 2023 02:35:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 694B28E0001; Tue, 3 Jan 2023 02:35:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 55BC08E0002; Tue, 3 Jan 2023 02:35:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 470BE8E0001 for ; Tue, 3 Jan 2023 02:35:38 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 1918EC061D for ; Tue, 3 Jan 2023 07:35:38 +0000 (UTC) X-FDA: 80312677956.30.032BC1A Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) by imf12.hostedemail.com (Postfix) with ESMTP id 66AAE40005 for ; Tue, 3 Jan 2023 07:35:35 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=B9LailS7; spf=pass (imf12.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.221.41 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1672731335; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=olkDH2t4VBXvPJ9F7B1IDdQPQzTSq2Hh4INNuTPeN5E=; b=iqF2DcA2II4QkvdQZ61Zelr/MhZtw3KiMss7Cd6G8JAAFBLWX0/N54LhQC19OtqgT47u2E d3LYWUmdQ8h8/imJUD3HROkVFwsTn6ptnpxUo8lLnTSDytLAeiQkMjU4b7LkczgfubT8h+ 5XSxY2VWXJ6xPobrE/WxMQ+zeMVz2f8= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=B9LailS7; spf=pass (imf12.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.221.41 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1672731335; a=rsa-sha256; cv=none; b=T+22qA9vdKVyeDuc1z4K9D0C1jFOPDsg6E62KrqipF8RBGem5rkzPnlXjLYJNktxLV0Z5n SZ7028EMRRUfzBPuV+R3SmP238PV0HJBSJbW39nY4gRKgOU/tmenpKOJBr+GNByf2YNbvd FBkLIiQHaPxkvgF0Qt6fwRvId2dCK00= Received: by mail-wr1-f41.google.com with SMTP id bk16so15375825wrb.11 for ; Mon, 02 Jan 2023 23:35:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=olkDH2t4VBXvPJ9F7B1IDdQPQzTSq2Hh4INNuTPeN5E=; b=B9LailS7DOn04LvBk+Z6cnNw6YKoWpOJyfjAnQuyaz4724rUCP68vBMv47yxbgN0x9 uwWqfnOhWPm4sPyY6LgnIyOhRadnYQWsJWnLlPcpTOA4aCi1sOmwIMFtfZ7gBQYl8ktS PwZHSAThncQmrsrLtnXvSDqbv6rrFV5VVFZwSDv0VwbvrNrpF8sJZ7KB6tAgkkTw2jcS mFQtOGIU/DP3ExpzVMVANgLVzfB4PYX7g/Y7TpnpxJ12xKOTR/6UkSZqM05hXT/9f4bN bpnpgt3gkHmJoZat8baIf1t2PSEVgw9M4gWkFouNPMeGiImP004tDVahH5t7vQWjQeH3 lWJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=olkDH2t4VBXvPJ9F7B1IDdQPQzTSq2Hh4INNuTPeN5E=; b=41XXjpTT5AYH43pSAKjcZUuSImZxoBU9nQ8J6C0vEaG1GFYtPSEP9oS/bWK8cf/Dw5 jy+DkC+TDdF/bG7C2l8F+TI3izCn9PIkH3N7LUeW07okTIDCZ2YaN26QsOUkLx7aKxJ6 LqnlILfq9gN+9LJUYoB5UHgkbXlSdebUMKeZosazOn8lwxRq4zG3s96kbnNor69CNJOz mMPnscStkVtKwIijiOyDM19wwSOrj2PMv5FqVezq4KTLivX3+M/SRTesv8y3ElAopaw2 cvhlhaXhgjs0lXVCMb9Tzgqd/xQ+GtAnA+0trxiBTMXWXP6q5HUN+2sK6m0KNQGSoBDm xP7A== X-Gm-Message-State: AFqh2krFZQrGigRbFPQ3LJZTixID/BX1GQSyB3F4omvTY2sljDXQ1qiA AhmPprJ8/+6xLWdkJypsVHo= X-Google-Smtp-Source: AMrXdXuFc1E2j2e3nZY27VMCBHgDBhos9D1XGeor32FdaLtS+/7kCaB/3b23d2wYDAKJqdAy+Tay3w== X-Received: by 2002:adf:dfc3:0:b0:294:c208:c921 with SMTP id q3-20020adfdfc3000000b00294c208c921mr5660944wrn.42.1672731333897; Mon, 02 Jan 2023 23:35:33 -0800 (PST) Received: from localhost (host81-157-153-247.range81-157.btcentralplus.com. [81.157.153.247]) by smtp.gmail.com with ESMTPSA id o15-20020adfe80f000000b0028965dc7c6bsm16217396wrm.73.2023.01.02.23.35.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Jan 2023 23:35:33 -0800 (PST) Date: Tue, 3 Jan 2023 07:35:32 +0000 From: Lorenzo Stoakes To: Jaewon Kim Cc: riel@redhat.com, redkoi@virtuozzo.com, akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, jaewon31.kim@gmail.com Subject: Re: [PATCH] page_alloc: avoid the negative free for meminfo available Message-ID: References: <20230103072807.19578-1-jaewon31.kim@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230103072807.19578-1-jaewon31.kim@samsung.com> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 66AAE40005 X-Rspam-User: X-Stat-Signature: 76smdx3zadd8p6xm5ankgexydrzxrfim X-HE-Tag: 1672731335-300183 X-HE-Meta: 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 8jionAMf 1UKnIkpGRBLIrq9W/jys0S6Qt2/rtiZhiMrP65a+PSPkH77zFkx1NYyV3L9ESG2IpWvIh7FwlvDqK14uex4NIai8iZq55pcxB9iYl4iBn5Kc41tHu2XTspkMCebACac1XVpoUp0M58mf//PskB/ogzLTmfh6NWWsJHnfalVkVhXKinoM4kJaGUiJHOwKTIPe/2zl58EG/d4KdGAU= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000076, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jan 03, 2023 at 04:28:07PM +0900, Jaewon Kim wrote: > The totalreserve_pages could be higher than the free because of > watermark high or watermark boost. Handle this situation and fix it to 0 > free size. > > Signed-off-by: Jaewon Kim > --- > mm/page_alloc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 218b28ee49ed..e510ae83d5f3 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5948,6 +5948,8 @@ long si_mem_available(void) > * without causing swapping or OOM. > */ > available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages; > + if (available < 0) > + available = 0; > > /* > * Not all the page cache can be freed, otherwise the system will > -- > 2.17.1 > We already reset to zero at the end of the function, wouldn't resetting to zero here potentially skew the result?