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 5D4F6C433F5 for ; Tue, 23 Nov 2021 17:29:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D84996B0075; Tue, 23 Nov 2021 12:28:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D34C36B0078; Tue, 23 Nov 2021 12:28:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFC1A6B007B; Tue, 23 Nov 2021 12:28:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0128.hostedemail.com [216.40.44.128]) by kanga.kvack.org (Postfix) with ESMTP id B23A46B0075 for ; Tue, 23 Nov 2021 12:28:57 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 772028B757 for ; Tue, 23 Nov 2021 17:28:47 +0000 (UTC) X-FDA: 78840879894.25.9F7A0D8 Received: from mail-lf1-f51.google.com (mail-lf1-f51.google.com [209.85.167.51]) by imf17.hostedemail.com (Postfix) with ESMTP id 17A18F0001EA for ; Tue, 23 Nov 2021 17:28:46 +0000 (UTC) Received: by mail-lf1-f51.google.com with SMTP id t26so92552778lfk.9 for ; Tue, 23 Nov 2021 09:28:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0VQ/DXnMuEbx26lUPiWfkgXYKbsUMBeuhoLEdn1uwPY=; b=LjjIQiSAWqZ2g0LZZgrpgKZfI5OfBDS1vwZklGguJ7PGH9V/pvMAh4r5lAyFthu4EB Yo91sS5li38g/GvU5hE6NVpdFO3h0lq71jPgOPtozZRfYb1DfLmU8Z8MoVblkuGZb4aE umbqVrKyk1aDwEb772YUahRG9IkKUnK8y3tvzZf1OVOQg6my5h/21Y1IQ26cfN1CDWAk mNlFpZ+IT3DFTYRzyrZ5pNMIxbayTF5gIBGUVpOmQyk/0YX9pMUMKhyW7iEvua9S7hcA cI0HLDAeVPmkHe7vSXzPeKk3O7VK8McFSqUnsIr4l9b143K4wDyb8wP/IgJpaUf/xAck 7Zjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0VQ/DXnMuEbx26lUPiWfkgXYKbsUMBeuhoLEdn1uwPY=; b=Db3Svy27lyXgDyotJunNBADpwqe9jdqxGGN1FuJkUpJ5zRgmJExjsY4UJYIhqdwv+Q 7nvT1V+dGIjY2uE3nF+B030nEUk98Fpqds1iQ/74i/x4YduQuQeif19BsfH4Tt05c6+B +QuINVTSx0wvvJ9i9RsSfJVy07XgchfWS++4HUwZevBVzYJz+r7v6rG9oE9+GYdOsejx 5+chQ2427trBgEzboCxQwPfJI6Iv5zslqYPmyhGl/pibZDy0xfqBVw9b9xJMmpdUE7EW WK+tvibMGM/iyvJFPVQY9Gm+ucEFk3qGjVDqD5r0Jx3/TzxUorselCua+Sq6460kBqW3 5MQQ== X-Gm-Message-State: AOAM533dFUxu3Fflf/5HMSk7S+aBSmHifMIp64MIVf0zfrkUoCZWwZe7 +WnlbY3g9wEgpNOs5C/3XKCcByCi0lPFS4WTKct3Gg== X-Google-Smtp-Source: ABdhPJysD3LJp3obeHCcm6LaJbNT1NkcWYlv//jXgDLA2+KIrlDxanfCBMwXcLRyTJlpwDA8uvDhaNJKLOFm9MdGHls= X-Received: by 2002:ac2:4d0a:: with SMTP id r10mr6444054lfi.210.1637688525482; Tue, 23 Nov 2021 09:28:45 -0800 (PST) MIME-Version: 1.0 References: <20211120201230.920082-1-shakeelb@google.com> <25b36a5c-5bbd-5423-0c67-05cd6c1432a7@redhat.com> <1b30d06d-f9c0-1737-13e6-2d1a7d7b8507@redhat.com> <92fe0c31-b083-28c4-d306-da8a3cd891a3@redhat.com> <1b400921-8bef-8073-10f9-a7cbb09cfefe@redhat.com> In-Reply-To: <1b400921-8bef-8073-10f9-a7cbb09cfefe@redhat.com> From: Shakeel Butt Date: Tue, 23 Nov 2021 09:28:34 -0800 Message-ID: Subject: Re: [PATCH] mm: split thp synchronously on MADV_DONTNEED To: David Hildenbrand Cc: "Kirill A . Shutemov" , Yang Shi , Zi Yan , Matthew Wilcox , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 17A18F0001EA X-Stat-Signature: guch6tjm88xamngpqt1ungcjhwifmsfs Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=LjjIQiSA; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf17.hostedemail.com: domain of shakeelb@google.com designates 209.85.167.51 as permitted sender) smtp.mailfrom=shakeelb@google.com X-Rspamd-Server: rspam02 X-HE-Tag: 1637688526-567129 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 Tue, Nov 23, 2021 at 9:26 AM David Hildenbrand wrote: > > On 23.11.21 18:24, Shakeel Butt wrote: > > On Tue, Nov 23, 2021 at 9:20 AM David Hildenbrand wrote: > >> > >> On 23.11.21 18:17, Shakeel Butt wrote: > >>> On Tue, Nov 23, 2021 at 8:57 AM David Hildenbrand wrote: > >>>> > >>> [...] > >>>>>> > >>>>>> I do wonder which these locking contexts are exactly, and if we could > >>>>>> also do the same thing on ordinary munmap -- because I assume it can be > >>>>>> similarly problematic for some applications. > >>>>> > >>>>> This is a good question regarding munmap. One main difference is > >>>>> munmap takes mmap_lock in write mode and usually performance critical > >>>>> applications avoid such operations. > >>>> > >>>> Maybe we can extend it too most page zapping, if that makes things simpler. > >>>> > >>> > >>> Do you mean doing sync THP split for most of page zapping functions > >>> (but only if that makes things simpler)? > >>> > >> > >> Yes -- if there are no downsides. > >> > > > > I will try. At the moment the assumption of "Not null zap_details > > implies leave swap entries" is giving me a headache. > > Not only you, did you stumble over > > https://lkml.kernel.org/r/20211115134951.85286-1-peterx@redhat.com > > already? > Oh thanks for the pointer. I missed that. I will take a look. Thanks again.