From patchwork Tue Jan 19 04:39:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 12028565 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=-11.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E036AC433DB for ; Tue, 19 Jan 2021 04:39:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 525E520867 for ; Tue, 19 Jan 2021 04:39:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 525E520867 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 776966B0031; Mon, 18 Jan 2021 23:39:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 726B08D002E; Mon, 18 Jan 2021 23:39:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 615B18D002D; Mon, 18 Jan 2021 23:39:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0074.hostedemail.com [216.40.44.74]) by kanga.kvack.org (Postfix) with ESMTP id 4AC6D6B0031 for ; Mon, 18 Jan 2021 23:39:24 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0EA441EE6 for ; Tue, 19 Jan 2021 04:39:24 +0000 (UTC) X-FDA: 77721270648.03.crow26_5e0867f2754f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id E501528A4E9 for ; Tue, 19 Jan 2021 04:39:23 +0000 (UTC) X-HE-Tag: crow26_5e0867f2754f X-Filterd-Recvd-Size: 8047 Received: from mail-qt1-f173.google.com (mail-qt1-f173.google.com [209.85.160.173]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 Jan 2021 04:39:23 +0000 (UTC) Received: by mail-qt1-f173.google.com with SMTP id v3so10609091qtw.4 for ; Mon, 18 Jan 2021 20:39:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=I8esbi1Mx4J8IdOq6n4ofQCTgaRlztGeZtwqoeCWczo=; b=Yv69/o5cvqCBTABqLZs9p1t/3TLh9bv+0w5Y9PKDnkyNKgtjzlS7A3rUbgTnJO/Ay3 UhN1+Z7Lne30j3dgRdbv7a8bNyniMD2z91FiDTMB91FVs8Stv/0iFlvGU/CaC9EJkhK6 hEMEp7fNsGfFovYJdGXlnIyi2xVRJxr13Xodf0F1mKqVuhxTzOiR1Z3g8LWRCi9+F/Z/ 1l7s2n63gYeVWeqvVJDznvZUeem+b5lr3nbKk+ZdZZ8eaTZ3Cudv6wmvkDRwa3BfvTVD AZk409FzOrU562MVLVD2ydzvIQ2K26Fzh4T6d2US2CrBwztxVxZU+hZjQOAfpJ2A0TFf rFpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=I8esbi1Mx4J8IdOq6n4ofQCTgaRlztGeZtwqoeCWczo=; b=iLdCX9y/aXItWfNpCHlkXBDAUEu02lWkKMNtYbyVKDdwxF2DFgpLiq88nkbosxY+28 eb0oLfZfLkm9Hjo7cX6hjZRomrsfabKeigrVJ/25NgcRFy+RNGT6c29q8nAHPOnruV0N 12mIkYLV6VqU9j3EK21nIEQmpzKC6P3hNpA4U9Rf8rt+f4NTWPIwUZu2G+6zPX9NKshm JxQOqZhQH1M4CnHihAgQ+oM81t0sjn1m/ZoefMUbRXDCE9UhoX8pIfnnVVj1xHxfFHnT htQ9zhwir/fdjkuyI53PeNb0dZjTkP1PeGpC8wkzotvb9jvXOc4HY9jFlnUHSf4QBflW egog== X-Gm-Message-State: AOAM530+LSor1u6yitwmmGEshjSKqFi6gf8Vp/dw/NEmWm/Ey64kpvMt +BHCLLi2vZ3019eqDPQs4WTL0A== X-Google-Smtp-Source: ABdhPJw9TiVm74D4hybB87XquFGGpJFw+ROPRyG8VTFzz3IeI7FyzoNv+6Ei9Eu1azikyTYgAD2g+A== X-Received: by 2002:aed:3064:: with SMTP id 91mr2681138qte.151.1611031162738; Mon, 18 Jan 2021 20:39:22 -0800 (PST) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id z20sm11934536qkz.37.2021.01.18.20.39.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Jan 2021 20:39:22 -0800 (PST) From: Pavel Tatashin To: pasha.tatashin@soleen.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, vbabka@suse.cz, mhocko@suse.com, david@redhat.com, osalvador@suse.de, dan.j.williams@intel.com, sashal@kernel.org, tyhicks@linux.microsoft.com, iamjoonsoo.kim@lge.com, mike.kravetz@oracle.com, rostedt@goodmis.org, mingo@redhat.com, jgg@ziepe.ca, peterz@infradead.org, mgorman@suse.de, willy@infradead.org, rientjes@google.com, jhubbard@nvidia.com, linux-doc@vger.kernel.org, ira.weiny@intel.com, linux-kselftest@vger.kernel.org Subject: [PATCH v5 00/14] prohibit pinning pages in ZONE_MOVABLE Date: Mon, 18 Jan 2021 23:39:06 -0500 Message-Id: <20210119043920.155044-1-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 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: Changelog --------- v5 - Added the following patches to the beginning of series, which are fixes to the other existing problems with CMA migration code: mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors also at the beginning of series mm/gup: do not allow zero page for pinned pages - remove .gfp_mask/.reclaim_idx changes from mm/vmscan.c - update movable zone header comment in patch 8 instead of patch 3, fix the comment - Added acked, sign-offs - Updated commit logs based on feedback - Addressed issues reported by Michal and Jason. - Remove: #define PINNABLE_MIGRATE_MAX 10 #define PINNABLE_ISOLATE_MAX 100 Instead: fail on the first migration failure, and retry isolation forever as their failures are transient. - In self-set addressed some of the comments from John Hubbard, updated commit logs, and added comments. Renamed gup->flags with gup->test_flags. v4 - Address page migration comments. New patch: mm/gup: limit number of gup migration failures, honor failures Implements the limiting number of retries for migration failures, and also check for isolation failures. Added a test case into gup_test to verify that pages never long-term pinned in a movable zone, and also added tests to fault both in kernel and in userland. v3 - Merged with linux-next, which contains clean-up patch from Jason, therefore this series is reduced by two patches which did the same thing. v2 - Addressed all review comments - Added Reviewed-by's. - Renamed PF_MEMALLOC_NOMOVABLE to PF_MEMALLOC_PIN - Added is_pinnable_page() to check if page can be longterm pinned - Fixed gup fast path by checking is_in_pinnable_zone() - rename cma_page_list to movable_page_list - add a admin-guide note about handling pinned pages in ZONE_MOVABLE, updated caveat about pinned pages from linux/mmzone.h - Move current_gfp_context() to fast-path --------- When page is pinned it cannot be moved and its physical address stays the same until pages is unpinned. This is useful functionality to allows userland to implementation DMA access. For example, it is used by vfio in vfio_pin_pages(). However, this functionality breaks memory hotplug/hotremove assumptions that pages in ZONE_MOVABLE can always be migrated. This patch series fixes this issue by forcing new allocations during page pinning to omit ZONE_MOVABLE, and also to migrate any existing pages from ZONE_MOVABLE during pinning. It uses the same scheme logic that is currently used by CMA, and extends the functionality for all allocations. For more information read the discussion [1] about this problem. [1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQSj80_w@mail.gmail.com Previous versions: v1 https://lore.kernel.org/lkml/20201202052330.474592-1-pasha.tatashin@soleen.com v2 https://lore.kernel.org/lkml/20201210004335.64634-1-pasha.tatashin@soleen.com v3 https://lore.kernel.org/lkml/20201211202140.396852-1-pasha.tatashin@soleen.com v4 https://lore.kernel.org/lkml/20201217185243.3288048-1-pasha.tatashin@soleen.com Pavel Tatashin (14): mm/gup: don't pin migrated cma pages in movable zone mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN mm: apply per-task gfp constraints in fast path mm: honor PF_MEMALLOC_PIN for all movable pages mm/gup: do not allow zero page for pinned pages mm/gup: migrate pinned pages out of movable zone memory-hotplug.rst: add a note about ZONE_MOVABLE and page pinning mm/gup: change index type to long as it counts pages mm/gup: longterm pin migration cleaup selftests/vm: test flag is broken selftests/vm: test faulting in kernel, and verify pinnable pages .../admin-guide/mm/memory-hotplug.rst | 9 + include/linux/migrate.h | 1 + include/linux/mm.h | 11 ++ include/linux/mmzone.h | 9 +- include/linux/sched.h | 2 +- include/linux/sched/mm.h | 27 +-- include/trace/events/migrate.h | 3 +- mm/gup.c | 178 ++++++++---------- mm/gup_test.c | 29 +-- mm/gup_test.h | 3 +- mm/hugetlb.c | 4 +- mm/page_alloc.c | 33 ++-- tools/testing/selftests/vm/gup_test.c | 36 +++- 13 files changed, 185 insertions(+), 160 deletions(-)