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 41535C28D13 for ; Mon, 22 Aug 2022 23:20:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ADEDB8D0001; Mon, 22 Aug 2022 19:20:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A66FE6B0074; Mon, 22 Aug 2022 19:20:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E08D8D0001; Mon, 22 Aug 2022 19:20:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 779BF6B0073 for ; Mon, 22 Aug 2022 19:20:54 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 523D51612EA for ; Mon, 22 Aug 2022 23:20:54 +0000 (UTC) X-FDA: 79828800828.29.EC6F0C6 Received: from mail-vs1-f51.google.com (mail-vs1-f51.google.com [209.85.217.51]) by imf15.hostedemail.com (Postfix) with ESMTP id 11035A000D for ; Mon, 22 Aug 2022 23:20:53 +0000 (UTC) Received: by mail-vs1-f51.google.com with SMTP id 190so4611433vsz.7 for ; Mon, 22 Aug 2022 16:20:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=mBK6+o6j2+LotCf9yizAJHX+fJSdClQm/ts8RAL5b8U=; b=sqD+PAPbDVU9CLXulqfqsL3lHh3OuDUG94kxY4GfaAGOv0bWY0XrU48QjChcINwFtf salod/xp4xKGuALe3sFKfA9Bj0ArmA16BjiA2XMNitS1fl0IUaRnIuXKsMwMuckTUdVG RChpp9PDTMb4WwKcwizkIwdIhteub8KOQsqNx7Ue78k59/Gb4okiIcbNqtNW27NiuZdX Vt7+OnUE9E8XMjHf/KC5y4a4Hly+6TTcA8h2zmcXcV5nsgQ/1SOe9UR2m6ShM9IHqUPY 7NK0E7YlzRPj/fYfFRfMff+NihzP43hxumJ6cEEL8iGvXKK/OGdf4N549ralRG1mt8U+ 9vlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=mBK6+o6j2+LotCf9yizAJHX+fJSdClQm/ts8RAL5b8U=; b=N+mfP7fA2bVQa3xnx82OWrqmYympABJUG2GnRVAEJ87UABDXjFPIEfu7TWXXzuNbIw DFVAtuQeUR7C8AnefKIDbVq0HEOeFVQe2umJxrcOr77MmExj5/fAC8ZOYT8N5OdPqLq9 CFqbtxztVHHf6b7bRRzCLEcmQd/O++/tOw1Q/YKryx0Mn+sHUu+/uJRZDKrXzIwuwG0W WH9qndhVSnqVE1UIaglwTe+NmLaVp0zMmtdEcIUe8thrRLJ7qjKISqalW6Vf1xCpNP7t n1rkg/bK8HCwaGBTBpYlvZNK/wVsfnnjTesi7Iq0dhwcVlTCDEM1cfteuRZ9ErSlfaZ2 sKpQ== X-Gm-Message-State: ACgBeo1RP5slUAatxIDPGzivsV1ZdiGd39z4d1G5EitnT6q0hJU0kZR4 y08WWT0EyRDB49xCr5zfnQaWPDIFiEQEjzks1+WRZA== X-Google-Smtp-Source: AA6agR5sKW4nrM3CN3TZoWhDbp0nd4726mDl9MWrNuIWkNfHs3XGmx2OlWmpPeTyS5Xs7YN96PqFfc2LP10bn8wnLA8= X-Received: by 2002:a67:d504:0:b0:390:3c26:7aa2 with SMTP id l4-20020a67d504000000b003903c267aa2mr5290241vsj.15.1661210453110; Mon, 22 Aug 2022 16:20:53 -0700 (PDT) MIME-Version: 1.0 References: <20220531223100.510392-1-surenb@google.com> <20220531223100.510392-2-surenb@google.com> <20220822152119.96d40c884078229ee3e6b25e@linux-foundation.org> <20220822154822.366a9e4527b748cf99d98637@linux-foundation.org> <20220822161603.9e19edfe2daaea3bf591910a@linux-foundation.org> In-Reply-To: <20220822161603.9e19edfe2daaea3bf591910a@linux-foundation.org> From: Yu Zhao Date: Mon, 22 Aug 2022 17:20:17 -0600 Message-ID: Subject: Re: [PATCH RESEND v2 2/2] mm: delete unused MMF_OOM_VICTIM flag To: Andrew Morton Cc: Suren Baghdasaryan , Michal Hocko , David Rientjes , Matthew Wilcox , Johannes Weiner , Roman Gushchin , Minchan Kim , "Kirill A . Shutemov" , Andrea Arcangeli , brauner@kernel.org, Christoph Hellwig , oleg@redhat.com, David Hildenbrand , Jann Horn , Shakeel Butt , Peter Xu , John Hubbard , shuah@kernel.org, linux-kernel , Linux-MM , linux-kselftest@vger.kernel.org, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=sqD+PAPb; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf15.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.51 as permitted sender) smtp.mailfrom=yuzhao@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661210454; a=rsa-sha256; cv=none; b=rDUJAuD2cXIzjTENaZ1Cdt8R6TpVkVnA7XZRIYxqqK6vCOht5umhH3QF7GenqVm4xbN+B6 U0OM9VCewSj62JpCd3XqZ+3cC4+oLwdENjyIMQG0Vxuu9ZBH5KNfLOzYdYmlSfZQctat7x RP0JhzfY+ceBaUVcYORGnFrTQv6nv5M= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661210454; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=mBK6+o6j2+LotCf9yizAJHX+fJSdClQm/ts8RAL5b8U=; b=JySMEgfbFU/Z8Ti2DKg9oRy0vXPGZ87o7D0N569+c6f66ZNgk8CK3vIl41Lg9YOtmbQxE9 2c+FHIs0v1Y12jr2mpJk4AlUWnL6zEvr/ObJUPKVVVOPM5hja1g723Z5hPYsR8zCSWrfbW gqnCwbZeU6zDZNvm6EcCX3bSFJiJLpg= X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=sqD+PAPb; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf15.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.51 as permitted sender) smtp.mailfrom=yuzhao@google.com X-Stat-Signature: zcq8xbu9e4kib1bunn3o4jkj3qeuzfnq X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 11035A000D X-HE-Tag: 1661210453-329579 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, Aug 22, 2022 at 5:16 PM Andrew Morton wrote: > > On Mon, 22 Aug 2022 16:59:29 -0600 Yu Zhao wrote: > > > > > @@ -4109,7 +4109,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned > > > > long start, unsigned long end, > > > > > > > > walk_pmd_range(&val, addr, next, args); > > > > > > > > - if (mm_is_oom_victim(args->mm)) > > > > + if (test_bit(MMF_OOM_REAP_QUEUED, &args->mm->flags)) > > > > return 1; > > > > > > > > /* a racy check to curtail the waiting time */ > > > > > > Oh. Why? What does this change do? > > > > The MMF_OOM_REAP_QUEUED flag is similar to the deleted MMF_OOM_VICTIM > > flag, but it's set at a later stage during an OOM kill. > > > > When either is set, the OOM reaper is probably already freeing the > > memory of this mm_struct, or at least it's going to. So there is no > > need to dwell on it in the reclaim path, hence not about correctness. > > Thanks. That sounds worthy of some code comments? Will do. Thanks.