From patchwork Mon Apr 29 17:13:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shakeel Butt X-Patchwork-Id: 10922135 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3F35092A for ; Mon, 29 Apr 2019 17:13:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2556828843 for ; Mon, 29 Apr 2019 17:13:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1929A2884F; Mon, 29 Apr 2019 17:13:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0BFE5285B0 for ; Mon, 29 Apr 2019 17:13:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728924AbfD2RNt (ORCPT ); Mon, 29 Apr 2019 13:13:49 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:52139 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728748AbfD2RNt (ORCPT ); Mon, 29 Apr 2019 13:13:49 -0400 Received: by mail-qt1-f201.google.com with SMTP id i38so6704972qte.18 for ; Mon, 29 Apr 2019 10:13:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=eAfjg0nGPcLWfxJJhGXBjl7FIwajcYkmLSUZC9BoAVo=; b=FKmZgoHbVGCO97K3BcQ+ic4v++s8rwzSXFy75ckZdej+bpKpVXnUNuY3AXrL33BVgJ Hqz2qDXRzmxVtOoIbcV+h21LE3UduSmU2SvSZoF6iZ6fTU/Uda98vcUkpqI6iB9iB4m3 ts6v/RxvQwZAPpQgbA2bqqm1snmfVmcGk/alcHvia2mC0gY7WxDx3MzXcsdnuqA/gMZJ XBYlW9aAVRGre8B6TOocT9qUo0Kl2vE6THP1e5dwTEiMa3I9hqxw/zuSjkYo1tPPGfr0 F47SccgEZEd4YLwQlE/5seZLLVVmyOrAhtyFNqs1W697mP3Z5oznCNev6CK6HYxdQwla tG+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=eAfjg0nGPcLWfxJJhGXBjl7FIwajcYkmLSUZC9BoAVo=; b=I07y/HLCvE/DWr8SGlFw3NFFOXN34t5LEKhNdISLmgJLYKcIkXHIC28M4j0igvjqGV ra2kKYTEdEACfDA/CMHoIaaWmSEm0HIwNVnBUjDnuGfX0KRmj9aLBpo3trMo1FGkgm3s qOyR37btlyIhJOPDsGQCt1Hgn6rxjm8cIax21QjR9rppsZ+IieJgb0XqbaFOfj1HGmhs 2Hy4D0DqdTf/tyl0DCd70cISzNXJeKPYQHvPXCpTigHXixCxfh8PYGeq4qu4RjoIymdg VbXb83IYIAPaxgzaqdOEJbNQyDAhwgfbTqL022iojzvgNzgJoicRBJ1vsPSmLTa1XxNL 0pYg== X-Gm-Message-State: APjAAAUQqN3yFEJvMA7SdyzZSictHmjjHleu4MA/v/kOnRNjBsByRj0Y ZY5r0t+d7c+IvzHPXxsseVzlV6b1Hk9nFg== X-Google-Smtp-Source: APXvYqwwgWs3zy3FLOkSJFSV4QCkVGyC8pGPoFtNLJRMe+t9+l0sHrdTDJroLj5qqsGFZEw5ucWIBmehPElR7Q== X-Received: by 2002:a0c:c18d:: with SMTP id n13mr19796452qvh.109.1556558027954; Mon, 29 Apr 2019 10:13:47 -0700 (PDT) Date: Mon, 29 Apr 2019 10:13:31 -0700 Message-Id: <20190429171332.152992-1-shakeelb@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH 1/2] memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL From: Shakeel Butt To: Johannes Weiner , Vladimir Davydov , Michal Hocko , Andrew Morton , Roman Gushchin , Jan Kara , Amir Goldstein Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Shakeel Butt Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The documentation of __GFP_RETRY_MAYFAIL clearly mentioned that the OOM killer will not be triggered and indeed the page alloc does not invoke OOM killer for such allocations. However we do trigger memcg OOM killer for __GFP_RETRY_MAYFAIL. Fix that. This flag will used later to not trigger oom-killer in the charging path for fanotify and inotify event allocations. Signed-off-by: Shakeel Butt Acked-by: Michal Hocko --- Changelog since v1: - commit message updated. mm/memcontrol.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2713b45ec3f0..99eca724ed3b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2294,7 +2294,6 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, unsigned long nr_reclaimed; bool may_swap = true; bool drained = false; - bool oomed = false; enum oom_status oom_status; if (mem_cgroup_is_root(memcg)) @@ -2381,7 +2380,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, if (nr_retries--) goto retry; - if (gfp_mask & __GFP_RETRY_MAYFAIL && oomed) + if (gfp_mask & __GFP_RETRY_MAYFAIL) goto nomem; if (gfp_mask & __GFP_NOFAIL) @@ -2400,7 +2399,6 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, switch (oom_status) { case OOM_SUCCESS: nr_retries = MEM_CGROUP_RECLAIM_RETRIES; - oomed = true; goto retry; case OOM_FAILED: goto force; From patchwork Mon Apr 29 17:13:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shakeel Butt X-Patchwork-Id: 10922139 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 653FA14B6 for ; Mon, 29 Apr 2019 17:14:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4BCC4285B0 for ; Mon, 29 Apr 2019 17:14:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F71028716; Mon, 29 Apr 2019 17:14:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D7ABE285B0 for ; Mon, 29 Apr 2019 17:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728928AbfD2ROE (ORCPT ); Mon, 29 Apr 2019 13:14:04 -0400 Received: from mail-pf1-f202.google.com ([209.85.210.202]:42454 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728776AbfD2ROE (ORCPT ); Mon, 29 Apr 2019 13:14:04 -0400 Received: by mail-pf1-f202.google.com with SMTP id d12so7605806pfn.9 for ; Mon, 29 Apr 2019 10:14:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=ZJZw+a1zAAS2yXCulVsapzFNzx2HgPG8quVXkMNIzRA=; b=LNHMaVmcposMzXiBxo+LfVRrsXl/hzH7pjhT+t1iPGrPl3ttT6JqRtwLI+LmJZzfO3 6dooMjOh7leRjuHd+y/PjbfED8ng26vganF2W2sFFNwLnXk6AO6Gnk27hUJRFq6vMHnD V/8GhLSaHioBm8HlcVfQcAoSlyZLZXgu6P3IdkSFLTkVAt1kTaAXh3IygzCUzwkRkMO2 ABs/JrSSCGKRasEP9mu0SQTJMLHuHvq8LSeIkgusJW0LAXLmHG7xmCeCdF9OyEsbz3k2 Ag2CxRX2t31eXoE9nTs+JsO7/i88GZiSYPqm/ZR7APmhOvzuNg5tIpU4XhI4eSSqDaiw t5+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=ZJZw+a1zAAS2yXCulVsapzFNzx2HgPG8quVXkMNIzRA=; b=hAE07AYdKFQHWtnGf0+meeHff5RjTlK1NYGsPsju0mzCtEK/QzilBFDuqPZ4mYyQ8r i1YX1kG6l7Ue3VZvGaWqedBYRpK3Y+Fkyb2ILZcxUuKS0KxllJ23QMMwQQY+Msp0TbtE d6tN94zeYs/f25dalv8fXdiDIbYi+Ae/CQnT8MgtAeTtBTYcMKgKJUdhtNlNmq9j82ZT udYbwGSW3rz5xV26NMDU4Meqweo0ZPkpOP7EhhYsT93SFyo/q2qdfdlTPql3faTrZoNJ y0spYAxA8cc6r2g8SmfGQ2+ggNqNAetseSMob8ubAaT4mnlRoF2E43/0id4DQxB2bvDq yPyQ== X-Gm-Message-State: APjAAAXaT2nsOLooRgRAL8lvfGbdTqC55MgNqmE115k0JuxoHQf4ttZb o8lM36aw8d73cpATJmfZ9k++tn3xfiQtqA== X-Google-Smtp-Source: APXvYqzTjNvJrvL+jBUcp6W9VnuxIBNtyu3+LblRTc2xOWy1Rbb1xQgUwgBIVo88fNW8fifpkQ8drzhLbu6dhw== X-Received: by 2002:a65:5941:: with SMTP id g1mr60655155pgu.51.1556558043109; Mon, 29 Apr 2019 10:14:03 -0700 (PDT) Date: Mon, 29 Apr 2019 10:13:32 -0700 In-Reply-To: <20190429171332.152992-1-shakeelb@google.com> Message-Id: <20190429171332.152992-2-shakeelb@google.com> Mime-Version: 1.0 References: <20190429171332.152992-1-shakeelb@google.com> X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH 2/2] memcg, fsnotify: no oom-kill for remote memcg charging From: Shakeel Butt To: Johannes Weiner , Vladimir Davydov , Michal Hocko , Andrew Morton , Roman Gushchin , Jan Kara , Amir Goldstein Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Shakeel Butt Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The commit d46eb14b735b ("fs: fsnotify: account fsnotify metadata to kmemcg") added remote memcg charging for fanotify and inotify event objects. The aim was to charge the memory to the listener who is interested in the events but without triggering the OOM killer. Otherwise there would be security concerns for the listener. At the time, oom-kill trigger was not in the charging path. A parallel work added the oom-kill back to charging path i.e. commit 29ef680ae7c2 ("memcg, oom: move out_of_memory back to the charge path"). So to not trigger oom-killer in the remote memcg, explicitly add __GFP_RETRY_MAYFAIL to the fanotify and inotify event allocations. Signed-off-by: Shakeel Butt --- fs/notify/fanotify/fanotify.c | 4 +++- fs/notify/inotify/inotify_fsnotify.c | 7 +++++-- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 6b9c27548997..9aa5d325e6d8 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -282,13 +282,15 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, __kernel_fsid_t *fsid) { struct fanotify_event *event = NULL; - gfp_t gfp = GFP_KERNEL_ACCOUNT; + gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL; struct inode *id = fanotify_fid_inode(inode, mask, data, data_type); /* * For queues with unlimited length lost events are not expected and * can possibly have security implications. Avoid losing events when * memory is short. + * + * Note: __GFP_NOFAIL takes precedence over __GFP_RETRY_MAYFAIL. */ if (group->max_events == UINT_MAX) gfp |= __GFP_NOFAIL; diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index ff30abd6a49b..17c08daa1ba7 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -99,9 +99,12 @@ int inotify_handle_event(struct fsnotify_group *group, i_mark = container_of(inode_mark, struct inotify_inode_mark, fsn_mark); - /* Whoever is interested in the event, pays for the allocation. */ + /* + * Whoever is interested in the event, pays for the allocation. However + * do not trigger the OOM killer in the target memcg. + */ memalloc_use_memcg(group->memcg); - event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT); + event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL); memalloc_unuse_memcg(); if (unlikely(!event)) {