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 B6173C6FD19 for ; Thu, 16 Mar 2023 15:43:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 428C8900003; Thu, 16 Mar 2023 11:43:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D8CF900002; Thu, 16 Mar 2023 11:43:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 25292900003; Thu, 16 Mar 2023 11:43:24 -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 138E3900002 for ; Thu, 16 Mar 2023 11:43:24 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id C54B21209F6 for ; Thu, 16 Mar 2023 15:43:23 +0000 (UTC) X-FDA: 80575180686.24.5632D5E Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) by imf21.hostedemail.com (Postfix) with ESMTP id 097B51C001F for ; Thu, 16 Mar 2023 15:43:18 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=lNaFaGZV; dmarc=pass (policy=none) header.from=samsung.com; spf=pass (imf21.hostedemail.com: domain of p.raghav@samsung.com designates 210.118.77.12 as permitted sender) smtp.mailfrom=p.raghav@samsung.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1678981399; 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=cBS2uM3tktUpBRksdEzPpOkuP+mSr6w8d/dIJk6Yu7c=; b=od0deGQeUIwdc9LejXhd20pqd8+3hWTSC8aDgJooFX49aIhQJZuJFiG0OnuaOyb+SyPo6N uVvto173Mtan0b7Ad/9/aR8g2Ihp97aLOfdNGvvapVRl55/P1ozDAXvFN4ieafwpxd3RO/ bnLW1WAd3W6LQUI0C2v/dtkNAnpt5n4= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=lNaFaGZV; dmarc=pass (policy=none) header.from=samsung.com; spf=pass (imf21.hostedemail.com: domain of p.raghav@samsung.com designates 210.118.77.12 as permitted sender) smtp.mailfrom=p.raghav@samsung.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1678981399; a=rsa-sha256; cv=none; b=WqZ2LpTsgpAxvIR/3RUxw0oEMgF3zOpdnIkW7S3ixO1EPSwQZOrPYGLNZuklFEIkWGJ+7K 4z+ouUJsQGDNv/rINzolaKLygLXunlXSL2xbMsuv9aAsQa/DTClbG5h5F5wMQ2qtKYYoBm TQucNT3gDP63+KFoVPQX53+pWNTS5Ow= Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20230316154316euoutp0238a8689e227c9ff3ceb09edc23d71e06~M8K9LhGe33058930589euoutp02W for ; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20230316154316euoutp0238a8689e227c9ff3ceb09edc23d71e06~M8K9LhGe33058930589euoutp02W DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1678981396; bh=cBS2uM3tktUpBRksdEzPpOkuP+mSr6w8d/dIJk6Yu7c=; h=Date:From:Subject:To:CC:In-Reply-To:References:From; b=lNaFaGZVis8GLStNf2RtJtFGmJ6jqoFY55pGlvyiz4cGJB+EjOqzMs2MQ84ogmo8R M6lTZciDXmAmtxcOF6zTK7K5v7HTyJIN4ynIdb8Ig7CqEdsuOuCJYfuLoGX9x7J8+f HZM3XLLLgupKw2WxAMTovHWwY3vZTuykVROEOQBU= Received: from eusmges2new.samsung.com (unknown [203.254.199.244]) by eucas1p2.samsung.com (KnoxPortal) with ESMTP id 20230316154316eucas1p21cd038591cef74f6a9a568d49373c913~M8K9AM_ja0325503255eucas1p2E; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) Received: from eucas1p2.samsung.com ( [182.198.249.207]) by eusmges2new.samsung.com (EUCPMTA) with SMTP id 7A.55.09966.41933146; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) Received: from eusmtrp2.samsung.com (unknown [182.198.249.139]) by eucas1p2.samsung.com (KnoxPortal) with ESMTPA id 20230316154316eucas1p203d1cb0da33c72fa8972d10c04714826~M8K8lVKVd2685926859eucas1p2N; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) Received: from eusmgms1.samsung.com (unknown [182.198.249.179]) by eusmtrp2.samsung.com (KnoxPortal) with ESMTP id 20230316154316eusmtrp2443fd2834f946cf37fdb2f7a6e8ac9c9~M8K8klVu52087120871eusmtrp2s; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) X-AuditID: cbfec7f4-d4fff700000026ee-ee-64133914c561 Received: from eusmtip1.samsung.com ( [203.254.199.221]) by eusmgms1.samsung.com (EUCPMTA) with SMTP id 24.7F.08862.31933146; Thu, 16 Mar 2023 15:43:16 +0000 (GMT) Received: from CAMSVWEXC02.scsc.local (unknown [106.1.227.72]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20230316154315eusmtip1e15dd51f2e90d87f819a7015dab01d92~M8K8YZ6V31613816138eusmtip1P; Thu, 16 Mar 2023 15:43:15 +0000 (GMT) Received: from [192.168.8.107] (106.210.248.172) by CAMSVWEXC02.scsc.local (2002:6a01:e348::6a01:e348) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 16 Mar 2023 15:41:21 +0000 Message-ID: Date: Thu, 16 Mar 2023 16:41:20 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 From: Pankaj Raghav Subject: Re: [LSF/MM/BPF TOPIC] Cloud storage optimizations To: Keith Busch , Luis Chamberlain CC: Matthew Wilcox , Theodore Ts'o , Daniel Gomez , =?UTF-8?Q?Javier_Gonz=c3=a1lez?= , , , , , Dave Chinner , "Christoph Hellwig" Content-Language: en-US In-Reply-To: <367c04f8-f5f6-a628-c4a9-7534fa83eb88@samsung.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [106.210.248.172] X-ClientProxiedBy: CAMSVWEXC01.scsc.local (2002:6a01:e347::6a01:e347) To CAMSVWEXC02.scsc.local (2002:6a01:e348::6a01:e348) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrGKsWRmVeSWpSXmKPExsWy7djP87oilsIpBq/2K1psOXaP0WLl6qNM FpMOXWO02HtL22LP3pMsFvfW/Ge12Pd6L7PFjQlPGS1ae36yW/z+MYfNgcvj1CIJj80rtDw2 repk89j0aRK7x+Qbyxk9dt9sYPNoOnOU2ePzJrkAjigum5TUnMyy1CJ9uwSujN3XNrAUTOKu uPGvqIHxOkcXIyeHhICJxNNdH1m7GLk4hARWMEqcu7cZyvnCKHFgZwMLSJWQwGdGiZ3Xw2E6 eh4fhIovZ5RoOlkHVzNrVw1E825GieN/vjKDJHgF7CS27T/ODmKzCKhKHP11gwUiLihxcuYT IJuDQ1QgSuLF6zIQk01AS6KxE6xaWMBaYtOsPYwgYREBT4n/x1VBpjMLfGaSeDfrKBNIDbOA uMStJ/PBbE4Be4kd3x5AxTUlWrf/Zoew5SW2v53DDHG+ssSc1zug7FqJU1tuMYEMlRBYzSnx 4ek/NoiEi8SGWcegbGGJV8e3sEPYMhL/d0IskxColnh64zczRHMLo0T/zvVsIJdKAF3ddyYH osZRYt/1PiaIMJ/EjbeCEPfwSUzaNp15AqPqLKSAmIXknVlIXpiF5IUFjCyrGMVTS4tz01OL jfJSy/WKE3OLS/PS9ZLzczcxApPW6X/Hv+xgXP7qo94hRiYOxkOMEhzMSiK84SwCKUK8KYmV ValF+fFFpTmpxYcYpTlYlMR5tW1PJgsJpCeWpGanphakFsFkmTg4pRqYxK4aqZh0l8RKvXv/ ofFpQsGko8Lan7bVC8+d1DH911HvhEVn8v9vWZCXxNVSkFc2USHtSPTBSst1HQZPpz17/VHj +LEZ25Z1cZoU3Sy8mpW15cxWMdMjaVtrDDukKl/y8s6+GXY2/ZjgqTDHrMqulq3sLXdCT4v1 rv8TnaVqf0mcW3+jvYp45MtL9vP3MQduKmm9oTntyAazayWT/G5qL2JrTl5+YaruyQIV0x11 cmU7RC56Bp1wMrxlGHrf90b2CY7Dsyutfl0J/VGjEqe8WKmS30/Laf45S6vgrz//fXzNucKl ckOF1K8X7F5P63IOi/1fr36wzcebZ6pJoLLI0YC/n+vdMwSmR97vS/FXYinOSDTUYi4qTgQA mOV1fckDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrHIsWRmVeSWpSXmKPExsVy+t/xu7oilsIpBu+nMFlsOXaP0WLl6qNM FpMOXWO02HtL22LP3pMsFvfW/Ge12Pd6L7PFjQlPGS1ae36yW/z+MYfNgcvj1CIJj80rtDw2 repk89j0aRK7x+Qbyxk9dt9sYPNoOnOU2ePzJrkAjig9m6L80pJUhYz84hJbpWhDCyM9Q0sL PSMTSz1DY/NYKyNTJX07m5TUnMyy1CJ9uwS9jN3XNrAUTOKuuPGvqIHxOkcXIyeHhICJRM/j gyxdjFwcQgJLGSW2NRxghEjISHy68pEdwhaW+HOtiw2i6COjxLMJ+1hBEkICuxklTp32A7F5 Bewktu0/DtbAIqAqcfTXDRaIuKDEyZlPwGxRgSiJp3cOMXcxcnCwCWhJNHaClQsLWEtsmrWH ESQsIuAp8f+4KsgqZoHPTBJ9e6cyQ+y9wCwxuX0h2F5mAXGJW0/mM4HYnAL2Eju+PWCCiGtK tG7/zQ5hy0tsfzuHGeIBZYk5r3dA2bUSn/8+Y5zAKDoLyXmzkIydhWTULCSjFjCyrGIUSS0t zk3PLTbUK07MLS7NS9dLzs/dxAiM+G3Hfm7ewTjv1Ue9Q4xMHIyHGCU4mJVEeMNZBFKEeFMS K6tSi/Lji0pzUosPMZoCw2gis5Rocj4w5eSVxBuaGZgamphZGphamhkrifN6FnQkCgmkJ5ak ZqemFqQWwfQxcXBKNTBpu2cmfo8Wm50Z+XT9iStMu2qrq8NV/XhfezJZ/1rortb4d128tXHY tt3uiw98qC5VCUr527p74eliAdvXdfwBf3QLw2/8nT9bO/iwx+yYZf6fko6++m0R+liTOzg1 6sXWtXVL9p98EPVGVuZX40qBZ7c9KvJzcv1Nl7y/t8eN+e+0vWFWH/2+cM5ffUR06WXX266v Tk59e2h/eH+d34fmn//ChDIvffbP33OXPewaY4/YnsKNZwXe9cYvWl7S0pW78EnS3l6mPwrT On3aFGwuNAgH6KwRmMP+Ve7MLuZnQos/S11IVdjR/5Bhpv2UL6cPXSvy9bgRvZfrUMealAeH 59+z4br7McDUcT/nD645SizFGYmGWsxFxYkAaQaBGYEDAAA= X-CMS-MailID: 20230316154316eucas1p203d1cb0da33c72fa8972d10c04714826 X-Msg-Generator: CA X-RootMTR: 20230303223216eucas1p2517850ab1c4f98dc4e09d83673525983 X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20230303223216eucas1p2517850ab1c4f98dc4e09d83673525983 References: <367c04f8-f5f6-a628-c4a9-7534fa83eb88@samsung.com> X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 097B51C001F X-Stat-Signature: r6m6h6qw891a13a91tniw84pmt8chqw5 X-HE-Tag: 1678981398-5417 X-HE-Meta: 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 3jn+PwCF dlfSeWdzDZYJ6RyXZvt2tOi3ZzLSZ9HfZjR96jlGtXYw2BAT9uN5aZqKTSkZD5xZYLaYc9ePRwauBE2DbJBETPQqhLdA5yVwrLOW2pyWyz6qroCyEIzl4CtmLSEDhp6jP5jEzL2XaawEfPDQ= 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 2023-03-16 16:29, Pankaj Raghav wrote: > Hi Keith, > > On 2023-03-03 23:32, Keith Busch wrote: >>> Yes, clearly it says *yet* so that begs the question what would be >>> required? >> >> Oh, gotcha. I'll work on a list of places it currently crashes. >> > I started looking into this to see why it crashes when we increase the LBA > size of a block device greater than the page size. These are my primary > findings: > > - Block device aops (address_space_operations) are all based on buffer > head, which limits us to work on only PAGE_SIZE chunks. > > For a 8k LBA size, the stack trace you posted ultimately fails inside > alloc_page_buffers as the size will be > PAGE_SIZE. > > struct buffer_head *alloc_page_buffers(struct page *page, unsigned long > size, bool retry) > Aghh. Sorry for the ugly formatting: struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, bool retry) { struct buffer_head *bh, *head; gfp_t gfp = GFP_NOFS | __GFP_ACCOUNT; long offset; struct mem_cgroup *memcg, *old_memcg; if (retry) gfp |= __GFP_NOFAIL; /* The page lock pins the memcg */ memcg = page_memcg(page); old_memcg = set_active_memcg(memcg); head = NULL; offset = PAGE_SIZE; while ((offset -= size) >= 0) { // we will not go into this loop as offset will be negative ... ... } ... return head; // we return NULL for LBA size > 4k }