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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1614FC6FD1D for ; Tue, 4 Apr 2023 12:01:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234503AbjDDMB1 (ORCPT ); Tue, 4 Apr 2023 08:01:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234438AbjDDMB0 (ORCPT ); Tue, 4 Apr 2023 08:01:26 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1360E198C for ; Tue, 4 Apr 2023 05:01:25 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id q20so10148416pfs.2 for ; Tue, 04 Apr 2023 05:01:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1680609684; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=JFM6Zed11abmlBVD7n880cLrXrOUp4BMMkatUFd1HS4=; b=C3IHbT9a4dE1N/jaGCLtN3lKrMYD4nnS5UX6sAc6hfVHSVColH2cqvozCtO13/mbsu juY/nqUHLi/YDIQDqQioRnAZpFo64dTqxG7SxjbkPxUMfUc2I170GQlfhNqcR8l+zudk lfooWs7aODyvSG5du4yamkq9tEFjfIyyLmkW0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680609684; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JFM6Zed11abmlBVD7n880cLrXrOUp4BMMkatUFd1HS4=; b=8KS2DCGQ7GsIXkblZyJayztfahQZkVZWLNq3o+TnlKdcb5ja0GHIiKqdpQr1WE6/oU pSe9G+8ckEf8GACF2n8VESte16OKa38XzWbENdtsh/Le2XFO1xWrjhChw/k+d+kwACRB Xsx+hN+K5Gr7350DyLJo1Ll6uUxzpnsabnskJz6Qeum6lLZivn35wog2ryJlY1uOQ7eZ ybPVup51U5CFTwxMZ8nhHDCiZ6PuM5bt17OSz8mEbZo7cvvqsH0VQ8peg78X9nzBWSSn ctBdwbii4P099t4qXese5DrSe35OEIHzoBHdkAeBT7GXUNaoLC72q1iefKF4X2emN6Fl N59w== X-Gm-Message-State: AAQBX9d0qaECjZDj98z1g7DJ0z/b6MWGkuL8/oAZjTZLFgfXoyGkQ50B oo20vXssdAof+lLSaxv+r/2Ctw== X-Google-Smtp-Source: AKy350ZCcY3HX/mt7wXQZeGj97V6L7bBWjmnqXMIXPCVdC61pts3cVJwKCkX/w34d5NYlLxrb5OLyg== X-Received: by 2002:aa7:9a0c:0:b0:627:e342:7f0e with SMTP id w12-20020aa79a0c000000b00627e3427f0emr2078573pfj.30.1680609684479; Tue, 04 Apr 2023 05:01:24 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:959b:21ea:166b:c273]) by smtp.gmail.com with UTF8SMTPSA id a5-20020aa78645000000b00627f054a3cdsm8688028pfo.31.2023.04.04.05.01.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 Apr 2023 05:01:24 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: linux-mm@kvack.org, Peter Xu , Hugh Dickins Cc: Andrew Morton , Matthew Wilcox , "Kirill A . Shutemov" , Yang Shi , David Hildenbrand , Jiaqi Yan , linux-kernel@vger.kernel.org, David Stevens Subject: [PATCH v6 0/4] mm/khugepaged: fixes for khugepaged+shmem Date: Tue, 4 Apr 2023 21:01:13 +0900 Message-Id: <20230404120117.2562166-1-stevensd@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Stevens This series reworks collapse_file so that the intermediate state of the collapse does not leak out of collapse_file. Although this makes collapse_file a bit more complicated, it means that the rest of the kernel doesn't have to deal with the unusual state. This directly fixes races with both lseek and mincore. This series also fixes the fact that khugepaged completely breaks userfaultfd+shmem. The rework of collapse_file provides a convenient place to check for registered userfaultfds without making the shmem userfaultfd implementation care about khugepaged. Finally, this series adds a lru_add_drain after swapping in shmem pages, which makes the subsequent folio_isolate_lru significantly more likely to succeed. v5 -> v6: - Stop freezing the old pages so that we don't deadlock with mc_handle_file_pte and mincore. - Add missing locking around shmem charge rollback. - Rebase on mm-unstable (f01f73d64cb5). Beyond straightfoward conflicts, this involves adapting the fix for f520a742287e (i.e. an unhandled ENOMEM). - Fix bug with bounds used with vma_interval_tree_foreach. - Add a patch doing lru_add_drain after swapping in the shmem case. - Update/clarify some comments. - Drop ack on final patch v4 -> v5: - Rebase on mm-unstable (9caa15b8a499) - Gather acks v3 -> v4: - Base changes on mm-everything (fba720cb4dc0) - Add patch to refactor error handling control flow in collapse_file - Rebase userfaultfd patch with no significant logic changes - Different approach for fixing lseek race v2 -> v3: - Use XA_RETRY_ENTRY to synchronize with reads from the page cache under the RCU read lock in userfaultfd fix - Add patch to fix lseek race v1 -> v2: - Different approach for userfaultfd fix *** BLURB HERE *** David Stevens (4): mm/khugepaged: drain lru after swapping in shmem mm/khugepaged: refactor collapse_file control flow mm/khugepaged: skip shmem with userfaultfd mm/khugepaged: maintain page cache uptodate flag include/trace/events/huge_memory.h | 3 +- mm/khugepaged.c | 312 ++++++++++++++++------------- 2 files changed, 171 insertions(+), 144 deletions(-) -- 2.40.0.348.gf938b09366-goog