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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4246C4361B for ; Fri, 18 Dec 2020 12:28:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3B10923443 for ; Fri, 18 Dec 2020 12:28:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B10923443 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6E0996B006C; Fri, 18 Dec 2020 07:28:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 66A3F6B0070; Fri, 18 Dec 2020 07:28:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 532596B0071; Fri, 18 Dec 2020 07:28:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id 3A4626B006C for ; Fri, 18 Dec 2020 07:28:27 -0500 (EST) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 00313181AF5C2 for ; Fri, 18 Dec 2020 12:28:25 +0000 (UTC) X-FDA: 77606331012.02.ant66_2d11a322743d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id EA64410097AA9 for ; Fri, 18 Dec 2020 12:28:20 +0000 (UTC) X-HE-Tag: ant66_2d11a322743d X-Filterd-Recvd-Size: 4639 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Fri, 18 Dec 2020 12:27:12 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id j22so2894485eja.13 for ; Fri, 18 Dec 2020 04:25:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3lhuweqQlhHO7hy/V02BEkOocTAj67fYHbIRgEWFXLs=; b=MJ6K37SnOv0MOV1yNPGIsCJSfLdzIW59btJg0j0VNKWwYOIneNWAlzLezFS+4P1UIg kvtBTojCVh9e1FShHJeAPucWvI2ftbOUroXc3gg7yM9AHLhxecDsp8JqaLP16g3CYZ95 KNP1Cnk6441ZWkLzWsRgdtvMxmnJkXOKrDk8xEK6tCfLPgJxrVR4w/situU0UMdI+ZPY SogVsfeoRkuyNuOHCbCzgcc9dcFBT5d5ugBKWROYrsUZM6AezfJFecEcH9aIqwQZ1vsU gurHn2N1ewEy9LbesQUw63usbfVnz6ZqRvJr4uYOp33JrXL8bIpGh2UkjhHGhGLVcJy7 FOPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3lhuweqQlhHO7hy/V02BEkOocTAj67fYHbIRgEWFXLs=; b=MJgHqGUbab0IGsN8avJZaKD5+pZIAc+QFjrfCDXBfFENryWG+A0862076LGhvHh9Ks Kn3DFguxwaPwE6jLU4cf0gRy+nxTlfx2255PQKLd677iF/sEyZ8ufnnF0iVmwLxmmLNj i2Pb9dNEZmNjCqPQbOAP5TiPKAzTB0FV/RvljB9ME+cmznnNbZRq7UYBOOWep4Yudws8 tOC9B06C1rDXbSWYQaBaMnyCM87Aq91jWcsrXzfemeJE5lp1Zq+azOmxsiird2DSibyD XTUqpxnVWZk4z52sE3hhnmTVcB+9I73OM3OC8Yt3IE4dVLyqquJE9YG0UBXELN05OEfz JyLg== X-Gm-Message-State: AOAM533MIeT0VENbEsvbmyJJPD4OZyZvLLx/t/pU0oCWb+/7IWZVoQE1 m6eo8E1y0bpZBTt+rUyAQNh0W1lLuFOdSClkI9of9g== X-Google-Smtp-Source: ABdhPJxS61dnQ5BtpBbJ0RZj2DWMhhsRQ2d4te1FBg4JvHGVH2QxOB81QucqauKQ/kxnWqUevwveMDcth6n5BZbPruM= X-Received: by 2002:a17:906:ce51:: with SMTP id se17mr3761264ejb.314.1608294329649; Fri, 18 Dec 2020 04:25:29 -0800 (PST) MIME-Version: 1.0 References: <20201217185243.3288048-1-pasha.tatashin@soleen.com> <20201217185243.3288048-6-pasha.tatashin@soleen.com> <20201218094324.GT32193@dhcp22.suse.cz> In-Reply-To: <20201218094324.GT32193@dhcp22.suse.cz> From: Pavel Tatashin Date: Fri, 18 Dec 2020 07:24:53 -0500 Message-ID: Subject: Re: [PATCH v4 05/10] mm/gup: migrate pinned pages out of movable zone To: Michal Hocko Cc: LKML , linux-mm , Andrew Morton , Vlastimil Babka , David Hildenbrand , Oscar Salvador , Dan Williams , Sasha Levin , Tyler Hicks , Joonsoo Kim , mike.kravetz@oracle.com, Steven Rostedt , Ingo Molnar , Jason Gunthorpe , Peter Zijlstra , Mel Gorman , Matthew Wilcox , David Rientjes , John Hubbard , Linux Doc Mailing List , Ira Weiny , linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" 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 Fri, Dec 18, 2020 at 4:43 AM Michal Hocko wrote: > > On Thu 17-12-20 13:52:38, Pavel Tatashin wrote: > > + * 1. Pinned pages: (long-term) pinning of movable pages is avoided > > + * when pages are pinned and faulted, but it is still possible that > > + * address space already has pages in ZONE_MOVABLE at the time when > > + * pages are pinned (i.e. user has touches that memory before > > + * pinning). In such case we try to migrate them to a different zone, > > + * but if migration fails the pages can still end-up pinned in > > + * ZONE_MOVABLE. In such case, memory offlining might retry a long > > + * time and will only succeed once user application unpins pages. > > I still dislike this. Pinning can fail so there shouldn't be any reasons > to break MOVABLE constrain for something that can be handled. If > anything there should be a very good reasoning behind this decision > documented. This is basically current behaviour, after patch 8, we can never pin pages in the movable zone, so I will update this comment in that patch. Thank you, Pasha > -- > Michal Hocko > SUSE Labs