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 A8545C433EF for ; Tue, 23 Nov 2021 17:25:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 043A46B0072; Tue, 23 Nov 2021 12:25:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F34056B0074; Tue, 23 Nov 2021 12:25:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DFD1F6B0075; Tue, 23 Nov 2021 12:25:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id D248B6B0072 for ; Tue, 23 Nov 2021 12:25:00 -0500 (EST) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7D612180ED7BF for ; Tue, 23 Nov 2021 17:24:50 +0000 (UTC) X-FDA: 78840870024.01.AE5C74A Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com [209.85.167.41]) by imf16.hostedemail.com (Postfix) with ESMTP id 52EA4F0000AE for ; Tue, 23 Nov 2021 17:24:46 +0000 (UTC) Received: by mail-lf1-f41.google.com with SMTP id r26so6129048lfn.8 for ; Tue, 23 Nov 2021 09:24:49 -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=q3v5tuwubo1Sqo25YljRMSH93aSZXvRl+wIvvd6U3ZU=; b=s8FdILRbB4MwUJbbgSZDLZfX0YADrX+/ZT4Zo71UIBs1oOGadqltv5BJq2CTkv69dX l8/jXRHRPisXvAZVPECWU9RPJHffQ7jMla5ycK9bddKxvcjZRGgDIkdIHbZxJsP/068k E2mq9s6gdobiEE6L1P0GaJEwH4LpyS6Wc4vCNYuCNFHS8gLz15105s/9wFi0qRLBVfjj nh8/S+xSZBtqTYGTkHXpHwzYg1BiYtckmH99kmBzUae8c+6POz8xN6LgwzMreoYVxN1j FGGS6xmSfk78jXVLQRNxDDi7wtpM7T44V+IjJ8Q58hUy7kSn0t3/XwxKgFHxZWTicrD0 GMWA== 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=q3v5tuwubo1Sqo25YljRMSH93aSZXvRl+wIvvd6U3ZU=; b=Tw4Mz7usdgM/Dr0iYpxhFLrQmVkc3xdMe0EOKJX15cLPKmp1/BVA9ohNRN+ElozlOp SinXmrs/K/T4S5cvLEY+VXrSDwHxJr6RQ7Jen7c6US4cE8McSpu6n8L6qSE+YNII7jDe izmrXd8YUr6dyGDwwp9NeK/MZGmH9xgR/84G1yVQW/oWiP3oHROYfiMp60/5qMG3q4q/ zfmJ3V+LF5CNtRAPBxdl/vjAutp6Ld38sr7Ar1tL6QEuvcdTq/Oir8FvhQ230aXEBcFy cX32S2stZ44e37RjIJCVzEVDpCh/5EAb+bamMnZnLpu4Huig+kdCymAfwrauJLAu04Mg PeVg== X-Gm-Message-State: AOAM533kHbE19bldPllo6MJbPj9qcFX8xZmpSZJPPdQVO41/HMZmubut 2CyriOCNZhM4yO0lIg60YC3dSSHxXWfXz3VNOeJYkA== X-Google-Smtp-Source: ABdhPJzdfyB+tuEZ9WOI2PZj5AtUOHkQkdMYqJipk1D2jhejMhTzG2S03AnTr00LSAxyDn+S36UL3Qhz1QQ4uyt3N5k= X-Received: by 2002:a19:6412:: with SMTP id y18mr6804576lfb.494.1637688288026; Tue, 23 Nov 2021 09:24:48 -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> In-Reply-To: From: Shakeel Butt Date: Tue, 23 Nov 2021 09:24:36 -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-Stat-Signature: z93hcwa77efk4rnyhdpriar88sef79ix Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=s8FdILRb; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf16.hostedemail.com: domain of shakeelb@google.com designates 209.85.167.41 as permitted sender) smtp.mailfrom=shakeelb@google.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 52EA4F0000AE X-HE-Tag: 1637688286-287608 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 9:20 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. Thanks for the suggestions and your time.