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 1CBCBC7EE23 for ; Thu, 8 Jun 2023 10:51:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9A2E96B0072; Thu, 8 Jun 2023 06:51:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 92B4C8E0002; Thu, 8 Jun 2023 06:51:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A4D78E0001; Thu, 8 Jun 2023 06:51:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 6A8656B0072 for ; Thu, 8 Jun 2023 06:51:38 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 3DB94C0203 for ; Thu, 8 Jun 2023 10:51:38 +0000 (UTC) X-FDA: 80879264676.27.2AF768C Received: from mail-oi1-f170.google.com (mail-oi1-f170.google.com [209.85.167.170]) by imf09.hostedemail.com (Postfix) with ESMTP id 64F1C140011 for ; Thu, 8 Jun 2023 10:51:35 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=shopee.com header.s=shopee.com header.b=Kag095cz; spf=pass (imf09.hostedemail.com: domain of haifeng.xu@shopee.com designates 209.85.167.170 as permitted sender) smtp.mailfrom=haifeng.xu@shopee.com; dmarc=pass (policy=reject) header.from=shopee.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1686221495; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Ps3xEBUlTo7f8loMCsGDyMpKyduVCzzLK5zLOAo2FgA=; b=pdjm5wpp/l0103irz/68P05BXMhc3svw3H+NAqDf478FqEo+QJIN1yQDF5xJH5+Tx0pczX 6KqseQlHEfQZkUAPVJTXvwG56AJWlEOYV372GKw9JMggzrVhBqZC35z16ehg0stq9iPGAg pWD5YSaFhvgh5xaK0b8vEhFVvau6CRU= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=shopee.com header.s=shopee.com header.b=Kag095cz; spf=pass (imf09.hostedemail.com: domain of haifeng.xu@shopee.com designates 209.85.167.170 as permitted sender) smtp.mailfrom=haifeng.xu@shopee.com; dmarc=pass (policy=reject) header.from=shopee.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1686221495; a=rsa-sha256; cv=none; b=8F7kz1LQpJ9puyv7WkWhTfDGanhHzho+2K3AhafhT0IPl8IgCbVsRIZIonjvwhEKRzEl8t LDN+L4cL1L53etPiO06NI38aVdpO9JRWOik/5ThXv22Hy4onuBEX/SLQq6kPXG6rmUGYoT s4L9/FO6KcY5u6VMZIKFog0brga4QQg= Received: by mail-oi1-f170.google.com with SMTP id 5614622812f47-39a4eb67c5fso331088b6e.0 for ; Thu, 08 Jun 2023 03:51:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shopee.com; s=shopee.com; t=1686221494; x=1688813494; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=Ps3xEBUlTo7f8loMCsGDyMpKyduVCzzLK5zLOAo2FgA=; b=Kag095czxCEU7vOdxKYZ/d98TyXJFonRNM16ghzk2PL20EnQiixiPr/iWa2l47tliV XkK2Rb5wLA9XE+C70klonvxLrh1G87LUxWiGl/fVQBaXJaRuSMDXdDyvDNhk0lwtZZYR UcO8IQH2bctkoF24qDUkRYolVPAAuiqnEu6h2El5B+9dr0rlHZiB9AnM8CjfC6ELmr2Z AhqLj1MbQEmyJjq4L4Vy0nISNYXu8gf/9pEWSFFOZZYA5J+qLzDmXijxrwX6dRqTOc1v 4R9tw2hDnepnF0pRQqSW4aHVn2Z58L3HNVhU/OyC+xhgmDhHKi6AfZhTPuTefdy0TTzA MCQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686221494; x=1688813494; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=Ps3xEBUlTo7f8loMCsGDyMpKyduVCzzLK5zLOAo2FgA=; b=WTWG5u+00Ig1i2Q3TrFItw/AD2OmUO+5Fhuay7qKOc8wQC4YrrtY7uKgR0y4xxQfFM YlNoAwjb4UnqnRPQP4hb7/FPWeMTwV0jVUknLMbF151OuZZsMR86otUeEiJq3wOUbt9r jnSI5ZXr3h0axYXzdBh5wXbHxGvMh4HqBC8tH3Jo7NLgm4yfAieNieBFXTes3A/0SQDG apeoTGQZE2XUm6Ebeyc+Neq0OPC+LX1PKH4shdllgpk5r5ty/hxEMZPxFBKMuw8VdQ/V g+t65g/nyISGjMNIrb2xo1AQYGE1vnWPkaU+mIuhs4e9V8PvOuZK7lA2byegs0q0wsnX +BIw== X-Gm-Message-State: AC+VfDzIz+0zU5zU/FI1OGsRWyU22SEnrwKSPDeYFhMZ3RJ0Ikffn330 tudu9EVjqzbxDv0FRewBt2T3Qw== X-Google-Smtp-Source: ACHHUZ72N291wzl0vYRQgKoDRSxdlp+HNwZWEHyWBr30AaBo6mZsWxlOZiVzilpKC0RImlSen5qXSw== X-Received: by 2002:a54:450a:0:b0:39a:b7a3:7d5e with SMTP id l10-20020a54450a000000b0039ab7a37d5emr4820536oil.33.1686221494459; Thu, 08 Jun 2023 03:51:34 -0700 (PDT) Received: from [10.54.24.10] ([143.92.118.3]) by smtp.gmail.com with ESMTPSA id b15-20020a17090a010f00b00256799877ffsm1059500pjb.47.2023.06.08.03.51.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Jun 2023 03:51:34 -0700 (PDT) Message-ID: Date: Thu, 8 Jun 2023 18:51:30 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH] mm/mm_init.c: add debug messsge for dma zone To: Mike Rapoport , Michal Hocko Cc: David Hildenbrand , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230607090734.1259-1-haifeng.xu@shopee.com> <34f32148-24c3-09a3-8bec-9515139e15b1@shopee.com> <20230608101340.GI52412@kernel.org> From: Haifeng Xu In-Reply-To: <20230608101340.GI52412@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 64F1C140011 X-Rspam-User: X-Stat-Signature: 7oqk5mp4bybnttfzq9husikgzg5hm1jz X-Rspamd-Server: rspam01 X-HE-Tag: 1686221495-573939 X-HE-Meta: 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 ZuGT3iEj NGOM9Ux+sWWSiYX1DO5Lbel2Kdj0OJIbpP1KguM3iBwdA8LhOqhlQnzvQgHRTYpkR2wYitYzZyoDmW+FCD6z8bl+IlO7NvVtH/Oo9JDwFpORYcEmiCuvlNZ2rSeB2lCVperMFVS+ufsEnVdvzvB4e3eJIvIMtOa5Da4G1ADHCn1e5e2rt2ShC1pCDo4rBttoFMBBHsVHN/2LfVj3g9Ae45pDl2QUKNWLuM0rXHWB4HlJSnqB9F/9gY8WbjdHCou3v/I0lxJM3EYzPx/pV3H2Yi2RtYAeahd2ATGGDUA92hUB26O9eTldD2/TCQ4WKarRln56UmbSKRUx86x2U1eBOPsP7Ei05vB+Pw7p7iKD1lYEYYQ/zmyZkTjJZqcMnQewqlmvp+T/mEX827hKTSDL26nOcog== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2023/6/8 18:13, Mike Rapoport wrote: > On Thu, Jun 08, 2023 at 11:18:02AM +0200, Michal Hocko wrote: >> On Thu 08-06-23 15:38:48, Haifeng Xu wrote: >>> >>> >>> On 2023/6/7 18:22, David Hildenbrand wrote: >>>> On 07.06.23 12:16, Michal Hocko wrote: >>>>> On Wed 07-06-23 09:07:34, Haifeng Xu wrote: >>>>>> If freesize is less than dma_reserve, print warning message to report >>>>>> this case. >>>>> >>>>> Why? >>>> >>>> I'd like to second that question, and add >>>> >>>> a) Did you run into that scenario? >>>> b) What can an admin do in that case with that error messages? >>> >>> In theory，dma_reserve shouldn't exceed freesize, so the error messages can remind us >>> to verify whether the configuration of reserved memory is correct. >> >> I am not really convinced this is worth touching the code TBH. > > The only architecture that sets the dma_reserve is x86_64 and it sets it to > the number of reserved pages in DMA zone. There is no way freesize will be > less than dma_reserve. Yes. From the comments, x86_64 calculates the dma_reserve in order to set zone watermarks more accurately. But berfore init_per_zone_wmark_min(), memblock_free_all() has already recalculated the managed pages. It seems that the dma_reserve is not really helpful to this. > > I'm not sure that in general dma_reserve has some value now, but that's a > completely different story. > >> -- >> Michal Hocko >> SUSE Labs >