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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A8C6C00A5A for ; Tue, 17 Jan 2023 23:21:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229923AbjAQXV1 (ORCPT ); Tue, 17 Jan 2023 18:21:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbjAQXUi (ORCPT ); Tue, 17 Jan 2023 18:20:38 -0500 Received: from mail-yb1-xb2e.google.com (mail-yb1-xb2e.google.com [IPv6:2607:f8b0:4864:20::b2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D14B6B997 for ; Tue, 17 Jan 2023 13:09:34 -0800 (PST) Received: by mail-yb1-xb2e.google.com with SMTP id 123so2557521ybv.6 for ; Tue, 17 Jan 2023 13:09:34 -0800 (PST) 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:subject:date:message-id:reply-to; bh=E1pw3vOO82Ds9w0163Mtmi7QOVEF9Qab6422FSilTSc=; b=mTi6Cm+rzRtxi6oZLIJ91mSXwfcEY4a81qq/xNecU7vlrtpUR0JpUZwhomKtKdV/bH yATQfErPbZeyxcdUyrwsBWOSQi8RryHvk++rcz/w37nplP0mXTMxsOfNDarssjFI59pq xr/7egPGkEYgrPd2M84+OJzl0Gvc+HM4EftCB2pHv8VhI8/KQoFHXoj87lciP06arJYR b6NCAoEFSNtxVpc2Xa35GvApYPnqkvaTscxeFceDY0/WXM2I2CsL2bwcuP4vAlthafgX e/k0u6+zh4JdfVmiWfJDx6EnicyeOXe5BqhJwpOAEOaXveBALnLC//9uWtAWOKl1MqIc ZOxA== 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:subject:date:message-id :reply-to; bh=E1pw3vOO82Ds9w0163Mtmi7QOVEF9Qab6422FSilTSc=; b=P0q17sBGcOLlGCpbzMvK3i6SisOvOX9TRORxCyhtdut4Vuo1wbUihovcgZ4XBshmOj epzQ7Jh8d+PPnhJPU+KIGBYbFiENVjxOrIggPSqT70TAx9Ezj+sPBcN/lj9nGddgpvPY tz7kPzEzAb1epULDvJyJm/fRtyP28ZjQinrs44BxLD5EF6SWBictHXe0VCgA7Pa1OjsQ jXVImPqRoSEPqiLuafWaiyPHi4nf0rqCKZTXodhKGExuXeKT0p1bpLxl7j2nuiDxnlYM AdokCUSRFA6MYuevEYbS7Y2xAU87cjzGFCBHJZoWdiAuJUYmvwp9hgJBvhk1LQFjWSXx Gf9A== X-Gm-Message-State: AFqh2krcMCIED1EYi5GymWu3rXr5cC+Q8lMnK1u7BgQHxBFnKIHqt/7K BUvS7EU38ydy0y6NDdwG0bGogG42gKIcBeshREwMbA== X-Google-Smtp-Source: AMrXdXsOr+GEGkBosigfUHXu92KjE9VznkpfG3TQiLvk8vecH24hbrAEBO8q8YfqiqTC9f7Q1FqDZlNhJ6QWePgl6iw= X-Received: by 2002:a05:6902:685:b0:7e9:646d:2da3 with SMTP id i5-20020a056902068500b007e9646d2da3mr667784ybt.340.1673989773689; Tue, 17 Jan 2023 13:09:33 -0800 (PST) MIME-Version: 1.0 References: <20230109205336.3665937-1-surenb@google.com> <20230109205336.3665937-13-surenb@google.com> In-Reply-To: From: Suren Baghdasaryan Date: Tue, 17 Jan 2023 13:09:13 -0800 Message-ID: Subject: Re: [PATCH 12/41] mm: add per-VMA lock and helper functions to control it To: Michal Hocko Cc: akpm@linux-foundation.org, michel@lespinasse.org, jglisse@google.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 17, 2023 at 7:07 AM Michal Hocko wrote: > > On Mon 09-01-23 12:53:07, Suren Baghdasaryan wrote: > > diff --git a/kernel/fork.c b/kernel/fork.c > > index 5986817f393c..c026d75108b3 100644 > > --- a/kernel/fork.c > > +++ b/kernel/fork.c > > @@ -474,6 +474,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) > > */ > > *new = data_race(*orig); > > INIT_LIST_HEAD(&new->anon_vma_chain); > > + vma_init_lock(new); > > dup_anon_vma_name(orig, new); > > } > > return new; > > @@ -1145,6 +1146,9 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, > > seqcount_init(&mm->write_protect_seq); > > mmap_init_lock(mm); > > INIT_LIST_HEAD(&mm->mmlist); > > +#ifdef CONFIG_PER_VMA_LOCK > > + WRITE_ONCE(mm->mm_lock_seq, 0); > > +#endif > > The mm shouldn't be visible so why WRITE_ONCE? True. Will change to a simple assignment. > > -- > Michal Hocko > SUSE Labs