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 D8282C32792 for ; Mon, 22 Aug 2022 22:34:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 415A56B0073; Mon, 22 Aug 2022 18:34:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 39DF66B0074; Mon, 22 Aug 2022 18:34:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 217978D0001; Mon, 22 Aug 2022 18:34:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 0C2036B0073 for ; Mon, 22 Aug 2022 18:34:29 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id D3DF61206E1 for ; Mon, 22 Aug 2022 22:34:28 +0000 (UTC) X-FDA: 79828683816.02.1419E43 Received: from mail-ua1-f42.google.com (mail-ua1-f42.google.com [209.85.222.42]) by imf10.hostedemail.com (Postfix) with ESMTP id 97F30C0008 for ; Mon, 22 Aug 2022 22:34:28 +0000 (UTC) Received: by mail-ua1-f42.google.com with SMTP id cd25so4931379uab.8 for ; Mon, 22 Aug 2022 15:34:28 -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=iZ4aTKxmgzYAEVUnlcLNmF4cSAWmUwWq1yIkniS2lL0=; b=rtT+NsCSQka7KbyH7rAcBe92sgRFz606wyn75s7/lsMN+Hcw+JArgHz5ZqoCcW/8Rk zPa0OaypuRKQbIm/dttjw3wlbfBYGB+VeWZOeQ4Y8cdFOeaWpYEQW0ZaJ6pzZGsPoxmY //aByMBzPgAyM+2jHfOzM5sOLr8PTlp0IW4hx0M8wddu573kFri7H3v8UKlXpIcXDO8a r/NIQDmwPwK40IKxM99L1c733FRFNIpV0Euik7VpUNq3WGBJYcjY3DoKzCphZPkk268+ V7NaIVePZZK7OlMf1Stu0q0plaMhsb/2GMXh7/SSWgFERJJ6Uy2MVrl5WHmGm/rfC9+I LWiQ== 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=iZ4aTKxmgzYAEVUnlcLNmF4cSAWmUwWq1yIkniS2lL0=; b=lzol93fzvNt+AfzNh+cdwGJSjMaOan0STIdTBv2L8Ebk6BYMajuvqNgfHEDPPwBxjG Ojm320dqzlsrclvlJhU3tHd+UlvvoUtqCByRzlM66kao2n/WUXag+rnl8QcaDU1tRpA+ dzt9vNMfs7o4w0ybmu/0Y3PXUownRd/8QbDSC6ahq7bMle94OW0NYGbZ1X1Wv/5ZE7Pi HMG/UPrkOAN0vpUKa8sNCD6KyBRL3YZse66mAxVXmE/qRsqjQTdfiENrcNbnl9z8KZRC FmHsmChF6dcoBw0ftaD/s2nGZXn2nLAKMhrYctvAMnVMKylRpZZw8ebs1S0Qto7G28LD HNtA== X-Gm-Message-State: ACgBeo33rFqvD+atrvLNH3/DCnTlRWOACp42q/wrgG/Np6mwwMV6kAGd f+MLDY2Da3M/L1uSq+okSaUb1bFYfgl8onMd7hSeSQ== X-Google-Smtp-Source: AA6agR7IQdMHvp5x/ilzybc9F3dX6tIA926NxCQb6p6jY5QhGizH1xIddOda33LFsoE769hy9fge67U5zAGfEu8ZFEA= X-Received: by 2002:ab0:5ac1:0:b0:39f:1ea5:250e with SMTP id x1-20020ab05ac1000000b0039f1ea5250emr199069uae.70.1661207667742; Mon, 22 Aug 2022 15:34:27 -0700 (PDT) MIME-Version: 1.0 References: <20220531223100.510392-1-surenb@google.com> <20220531223100.510392-2-surenb@google.com> <20220822152119.96d40c884078229ee3e6b25e@linux-foundation.org> In-Reply-To: <20220822152119.96d40c884078229ee3e6b25e@linux-foundation.org> From: Yu Zhao Date: Mon, 22 Aug 2022 16:33:51 -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, hch@infradead.org, 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-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661207668; a=rsa-sha256; cv=none; b=rZt9MOY6yXW/ZZvsROGT1LiyylKPuMvGwKN4shz33gcXOOUpwLgfNXxpR6N/MFR0ofj/k8 0khWVwM7Qxk31L6R1ZW7x86V6YdngpXA3epWy7wyhRwBhfDPfPVu0SNH3tQJukUhshciMn mnZ0C9djEhj3F1MVgOjxLT0bvWlqU4M= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=rtT+NsCS; spf=pass (imf10.hostedemail.com: domain of yuzhao@google.com designates 209.85.222.42 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661207668; 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=iZ4aTKxmgzYAEVUnlcLNmF4cSAWmUwWq1yIkniS2lL0=; b=8BBjYzmu7VW/qUuS00XykPTRzwMJTJGEVv1yFM6qgcLvG6EcEckd12Wt4MPQ+uaqj2U9DO zWvXEJY4wJtmlpiNQK3qGroYqO1Z6R034OaUGdijoTMdS9/mevHJSEmup9gksmfztuiKKi oIfRPr5xx4P3Y/6h7lTqLMDOOt8mW/M= Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=rtT+NsCS; spf=pass (imf10.hostedemail.com: domain of yuzhao@google.com designates 209.85.222.42 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 97F30C0008 X-Stat-Signature: dm5i5acorqyqhbg5z7knqm5hrxndxwbn X-Rspam-User: X-HE-Tag: 1661207668-333046 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 4:21 PM Andrew Morton wrote: > > On Tue, 31 May 2022 15:31:00 -0700 Suren Baghdasaryan wrote: > > > With the last usage of MMF_OOM_VICTIM in exit_mmap gone, this flag is > > now unused and can be removed. > > > > ... > > > > --- a/include/linux/oom.h > > +++ b/include/linux/oom.h > > @@ -77,15 +77,6 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk) > > return tsk->signal->oom_mm; > > } > > > > -/* > > - * Use this helper if tsk->mm != mm and the victim mm needs a special > > - * handling. This is guaranteed to stay true after once set. > > - */ > > -static inline bool mm_is_oom_victim(struct mm_struct *mm) > > -{ > > - return test_bit(MMF_OOM_VICTIM, &mm->flags); > > -} > > - > > The patch "mm: multi-gen LRU: support page table walks" from the MGLRU > series > (https://lkml.kernel.org/r/20220815071332.627393-9-yuzhao@google.com) > adds two calls to mm_is_oom_victim(), so my build broke. > > I assume the fix is simply > > --- a/mm/vmscan.c~mm-delete-unused-mmf_oom_victim-flag-fix > +++ a/mm/vmscan.c > @@ -3429,9 +3429,6 @@ static bool should_skip_mm(struct mm_str > if (size < MIN_LRU_BATCH) > return true; > > - if (mm_is_oom_victim(mm)) > - return true; > - > return !mmget_not_zero(mm); > } > > @@ -4127,9 +4124,6 @@ restart: > > walk_pmd_range(&val, addr, next, args); > > - if (mm_is_oom_victim(args->mm)) > - return 1; > - > /* a racy check to curtail the waiting time */ > if (wq_has_sleeper(&walk->lruvec->mm_state.wait)) > return 1; > _ > > Please confirm? LGTM. The deleted checks are not about correctness. I've queued --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3402,7 +3402,7 @@ static bool should_skip_mm(struct mm_struct *mm, struct lru_gen_mm_walk *walk) if (size < MIN_LRU_BATCH) return true; - if (mm_is_oom_victim(mm)) + if (test_bit(MMF_OOM_REAP_QUEUED, &mm->flags)) return true; return !mmget_not_zero(mm); @@ -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 */