From patchwork Fri Jun 30 21:19:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 13298775 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 E121DEB64DD for ; Fri, 30 Jun 2023 21:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232287AbjF3VUE (ORCPT ); Fri, 30 Jun 2023 17:20:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229760AbjF3VUD (ORCPT ); Fri, 30 Jun 2023 17:20:03 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30B902680 for ; Fri, 30 Jun 2023 14:20:02 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-569e7aec37bso22916227b3.2 for ; Fri, 30 Jun 2023 14:20:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1688160001; x=1690752001; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=H9gcN3gNFu1WTtBUtpC0M4aYh2b9oslK18bWcyLDHdo=; b=oNIgkcP+Rm1zkUVn4t5u68ESvpgQIXbrcYw29/gRzdkE5UaATbVPes4z0XxKc6K6/p Jw15ZeO2phUHjjdXkz/Fm6vKj6Kxg45Foww+zGK4uOAGQqqs1BrsHBYIMr41Xjj7veyP /7nxOF0o6KW7tDm6OUT6bmkpjra0/KYvwtRBjY/lE/5NTj9I0EuMyZRtDufv8j+YeJo4 BurycZxKQ3Kva49nwAun+2C6w+cBong6Laauu/NCOZuov5J3VnHB+mmdeOgOOJr4/dpD PbfVskXqe6CffLh9wmpPLX7R5GUurnXto1SNVVdCYTODhlgKHpIMPgLptoHhfPs82CSh M/NQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688160001; x=1690752001; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=H9gcN3gNFu1WTtBUtpC0M4aYh2b9oslK18bWcyLDHdo=; b=WtF8yFZcte33vsTpDe2F/QACRMjMsL7FbU70IXmbFrjXfiDy8kNNwi+kpEeaADhn0F wl16XYvgy457aZ1E6+hnvb104ibPA/h+zYUR+mgLhbn76LK5H7rZWa9uhqNae6GsbJWK NDdfwdbC4b/gav6XvE7EjlP8Cc7pUyUqNfmoXZoqga+kP1e3pqo70SYD79HoBiplSvev lhXygVNrsVSW4AkO2Oi7OskO5a1693mcXP6X5aQAiaNmfxGIxkdCQ7ZBTAwOvmh2TvNK nyldQ/mtHBOU5S9dZFee8HqgPnumpeASII/SEbC5ORQM05MAJpX4tjRXWJ8+JgqrzUGz T+xQ== X-Gm-Message-State: ABy/qLYOXWxoT9uSi2mYIDz7K/RyDSRtevpZtpaniZRm273t9NznpMk3 cY2bLNFAuWEbnwiJuzjCHlvKP+0KdI4= X-Google-Smtp-Source: APBJJlFxz+5qjMtbjV4jvSAgVZ7fFk8uY3skGFQMChHy9vo8oYp4UdiT1As/B8NsDi05V0mv39s2UQ7kX1g= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:b54c:4d64:f00a:1b67]) (user=surenb job=sendgmr) by 2002:a81:bd01:0:b0:56c:e585:8b17 with SMTP id b1-20020a81bd01000000b0056ce5858b17mr27432ywi.5.1688160001126; Fri, 30 Jun 2023 14:20:01 -0700 (PDT) Date: Fri, 30 Jun 2023 14:19:51 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230630211957.1341547-1-surenb@google.com> Subject: [PATCH v7 0/6] Per-VMA lock support for swap and userfaults From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, hannes@cmpxchg.org, mhocko@suse.com, josef@toxicpanda.com, jack@suse.cz, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, michel@lespinasse.org, liam.howlett@oracle.com, jglisse@google.com, vbabka@suse.cz, minchan@google.com, dave@stgolabs.net, punit.agrawal@bytedance.com, lstoakes@gmail.com, hdanton@sina.com, apopple@nvidia.com, peterx@redhat.com, ying.huang@intel.com, david@redhat.com, yuzhao@google.com, dhowells@redhat.com, hughd@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, pasha.tatashin@soleen.com, surenb@google.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org When per-VMA locks were introduced in [1] several types of page faults would still fall back to mmap_lock to keep the patchset simple. Among them are swap and userfault pages. The main reason for skipping those cases was the fact that mmap_lock could be dropped while handling these faults and that required additional logic to be implemented. Implement the mechanism to allow per-VMA locks to be dropped for these cases. First, change handle_mm_fault to drop per-VMA locks when returning VM_FAULT_RETRY or VM_FAULT_COMPLETED to be consistent with the way mmap_lock is handled. Then change folio_lock_or_retry to accept vm_fault and return vm_fault_t which simplifies later patches. Finally allow swap and uffd page faults to be handled under per-VMA locks by dropping per-VMA and retrying, the same way it's done under mmap_lock. Naturally, once VMA lock is dropped that VMA should be assumed unstable and can't be used. Changes since v6 posted at [2] - 4/6 replaced the ternary operation in folio_lock_or_retry, per Matthew Wilcox - 4/6 changed return code description for __folio_lock_or_retry per Matthew Wilcox Note: patch 3/6 will cause a trivial merge conflict in arch/arm64/mm/fault.c when applied over mm-unstable branch due to a patch from ARM64 tree [3] which is missing in mm-unstable. [1] https://lore.kernel.org/all/20230227173632.3292573-1-surenb@google.com/ [2] https://lore.kernel.org/all/20230630020436.1066016-1-surenb@google.com/ [3] https://lore.kernel.org/all/20230524131305.2808-1-jszhang@kernel.org/ Suren Baghdasaryan (6): swap: remove remnants of polling from read_swap_cache_async mm: add missing VM_FAULT_RESULT_TRACE name for VM_FAULT_COMPLETED mm: drop per-VMA lock when returning VM_FAULT_RETRY or VM_FAULT_COMPLETED mm: change folio_lock_or_retry to use vm_fault directly mm: handle swap page faults under per-VMA lock mm: handle userfaults under VMA lock arch/arm64/mm/fault.c | 3 ++- arch/powerpc/mm/fault.c | 3 ++- arch/s390/mm/fault.c | 3 ++- arch/x86/mm/fault.c | 3 ++- fs/userfaultfd.c | 34 ++++++++++++---------------- include/linux/mm.h | 37 ++++++++++++++++++++++++++++++ include/linux/mm_types.h | 3 ++- include/linux/pagemap.h | 11 +++++---- mm/filemap.c | 37 +++++++++++++++--------------- mm/madvise.c | 4 ++-- mm/memory.c | 49 ++++++++++++++++++++++------------------ mm/swap.h | 1 - mm/swap_state.c | 12 ++++------ 13 files changed, 120 insertions(+), 80 deletions(-)