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 X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7BAEC54FCB for ; Tue, 21 Apr 2020 00:44:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6AD3E2070B for ; Tue, 21 Apr 2020 00:44:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FQPGxAaF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AD3E2070B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DF2A18E0005; Mon, 20 Apr 2020 20:44:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D56BC8E0003; Mon, 20 Apr 2020 20:44:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BF6F18E0005; Mon, 20 Apr 2020 20:44:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id A30B08E0003 for ; Mon, 20 Apr 2020 20:44:00 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 636A6181AEF2A for ; Tue, 21 Apr 2020 00:44:00 +0000 (UTC) X-FDA: 76730015040.16.stone11_7a40aa0070727 X-HE-Tag: stone11_7a40aa0070727 X-Filterd-Recvd-Size: 5617 Received: from mail-lf1-f66.google.com (mail-lf1-f66.google.com [209.85.167.66]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 00:43:59 +0000 (UTC) Received: by mail-lf1-f66.google.com with SMTP id g10so9201079lfj.13 for ; Mon, 20 Apr 2020 17:43:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YZRwrK1UjiJpxDYSszjRPtqs1cjLjLji6Aam7rS81wo=; b=FQPGxAaF17vSSjjng+SYnVVTyYVA5s2NG2nnA/4N5kDp/WGCIrb9f25On61fC0A+Mz ArASZ/MOC2sFxS+nTQb0i3heZ8Ll8zNSL8IdvP2+Mna+8oUk343fzXUGUxuQLgoMW1Z4 O1jPs/t5whKhm7gTkJBQZestxtL3Dmcfy7EBMApLi0iSO0KWfQQuLCxKrEFiTYNN/OWU h0Ilp90Q6OjyQ3npdWPqddwv5b8E9qdaHGsEOkd8UvwVHnCIO9+AnxuUgJmr+wM8tDXz 7krNt+EMRR4FeeU9CTQQ/Ufy7Dc5u+ind2EDMZ2YSGF7sRuDCng69DxqD8wNP25ug6Nz Ql8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YZRwrK1UjiJpxDYSszjRPtqs1cjLjLji6Aam7rS81wo=; b=Cpz7er75PYQzNWivy3/IbYW7MWwQn/u8MLMWuyYObXDLQUFPzfH21dtSZLEpNhIQg5 N7RUyWRYztLzu1J6bZ9YPdWgvJtLQuGkjSK5WfOt7K+lWqmJtddGSbyN+B0cBKRXN5wQ OPX9vMeI2FhLgDrD+15hQu3hmeNyGLXyUFDWcez0R+FPd+bLOFVkugUcbrNbAVV6noOz LEG+GNfKH8iyNZL3Sl98aZP5Lmxvrf2Fe1p+n08lwrOf9DuquUifozpa8qbEUfTwx4uh QEWuKFDlE3VvAKxRxzwPDxgB/Zmorm3HlpBkgcCLlNqWHiM07+EE2uB9QVqybL/0akmx s6mQ== X-Gm-Message-State: AGi0PuaUJgMEZ9uPwnkZEKLHxtZnRT5OkCXffdQBSfFi9oc7Pk4rFWoI Mp+/L7vL2szT7gil1OLt5vOGgXZWfDaMiQ7YKWQ9aw== X-Google-Smtp-Source: APiQypJA0kncl3JUukHJh3Fz03w09zxZUG/GX3THwphT5IE6WJ7yzeQ6IMtZBOX7BEGJ02BB50U5guI79IbFaZqJp2g= X-Received: by 2002:a05:6512:318a:: with SMTP id i10mr12195933lfe.96.1587429838243; Mon, 20 Apr 2020 17:43:58 -0700 (PDT) MIME-Version: 1.0 References: <20200420223936.6773-1-schatzberg.dan@gmail.com> <20200420223936.6773-3-schatzberg.dan@gmail.com> In-Reply-To: <20200420223936.6773-3-schatzberg.dan@gmail.com> From: Shakeel Butt Date: Mon, 20 Apr 2020 17:43:47 -0700 Message-ID: Subject: Re: [PATCH 2/4] mm: support nesting memalloc_use_memcg() To: Dan Schatzberg Cc: Jens Axboe , Alexander Viro , Jan Kara , Amir Goldstein , Tejun Heo , Li Zefan , Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Hugh Dickins , Roman Gushchin , Chris Down , Yang Shi , Ingo Molnar , "Peter Zijlstra (Intel)" , Mathieu Desnoyers , "Kirill A. Shutemov" , Andrea Arcangeli , Thomas Gleixner , "open list:BLOCK LAYER" , open list , "open list:FILESYSTEMS (VFS and infrastructure)" , "open list:CONTROL GROUP (CGROUP)" , "open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)" Content-Type: text/plain; charset="UTF-8" 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 Mon, Apr 20, 2020 at 3:41 PM Dan Schatzberg wrote: > > The memalloc_use_memcg() function to override the default memcg > accounting context currently doesn't nest. But the patches to make the > loop driver cgroup-aware will end up nesting: > > [ 98.137605] alloc_page_buffers+0x210/0x288 > [ 98.141799] __getblk_gfp+0x1d4/0x400 > [ 98.145475] ext4_read_block_bitmap_nowait+0x148/0xbc8 > [ 98.150628] ext4_mb_init_cache+0x25c/0x9b0 > [ 98.154821] ext4_mb_init_group+0x270/0x390 > [ 98.159014] ext4_mb_good_group+0x264/0x270 > [ 98.163208] ext4_mb_regular_allocator+0x480/0x798 > [ 98.168011] ext4_mb_new_blocks+0x958/0x10f8 > [ 98.172294] ext4_ext_map_blocks+0xec8/0x1618 > [ 98.176660] ext4_map_blocks+0x1b8/0x8a0 > [ 98.180592] ext4_writepages+0x830/0xf10 > [ 98.184523] do_writepages+0xb4/0x198 > [ 98.188195] __filemap_fdatawrite_range+0x170/0x1c8 > [ 98.193086] filemap_write_and_wait_range+0x40/0xb0 > [ 98.197974] ext4_punch_hole+0x4a4/0x660 > [ 98.201907] ext4_fallocate+0x294/0x1190 > [ 98.205839] loop_process_work+0x690/0x1100 > [ 98.210032] loop_workfn+0x2c/0x110 > [ 98.213529] process_one_work+0x3e0/0x648 > [ 98.217546] worker_thread+0x70/0x670 > [ 98.221217] kthread+0x1b8/0x1c0 > [ 98.224452] ret_from_fork+0x10/0x18 > > where loop_process_work() sets the memcg override to the memcg that > submitted the IO request, and alloc_page_buffers() sets the override > to the memcg that instantiated the cache page, which may differ. > > Make memalloc_use_memcg() return the old memcg and convert existing > users to a stacking model. Delete the unused memalloc_unuse_memcg(). > > Signed-off-by: Dan Schatzberg This patch was from Johannes, so I would suggest to keep his authorship and signoff along with your signoff. Reviewed-by: Shakeel Butt