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 876D8C4708E for ; Tue, 3 Jan 2023 07:35:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236801AbjACHfj (ORCPT ); Tue, 3 Jan 2023 02:35:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231239AbjACHfg (ORCPT ); Tue, 3 Jan 2023 02:35:36 -0500 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F083DEC5 for ; Mon, 2 Jan 2023 23:35:35 -0800 (PST) Received: by mail-wr1-x429.google.com with SMTP id t15so19731463wro.9 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=rJMd3A9NmPtjt6ygrjkJnEzJ9r4og51oqw7ZTqOcF4RGVUPXcWB6QmvTTd1tuJ+WyE gp4dLBqx30DL0ocWNj5tT1kPf3Xq25EaKTPOAEQA7LV5mIqVsirVDpwEEuB6nI7QkxXr Diro/XxwcOe/gHp1z42fElN7VtSGnAVHeB0MjI0C6qTeXonpmHZZDBu3M9vPpHuEa6M2 W1c2P+qAx8QP8NdteA13ztQMNkTMs93VReZoDbgwwRXHgMtmQRfPHZN0Jt8PdzUGlbkr RrXfjaUnJt0arBvHCXWMpFnfRAZpx936NYpkUsC7yJ9V53oPKlN56KYylaSxpCzHAkBd 0pdg== X-Gm-Message-State: AFqh2koXQj8mZEknWo7fE1NyKZX87u9lWe6xdOgFEKMT/DbvGHg7k0iI exKT1YNpxlMTvGpOIu7s5pI= 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> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?