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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2DC1EC433E9 for ; Thu, 14 Jan 2021 03:34:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F26C523788 for ; Thu, 14 Jan 2021 03:34:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727192AbhANDeP (ORCPT ); Wed, 13 Jan 2021 22:34:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726705AbhANDeO (ORCPT ); Wed, 13 Jan 2021 22:34:14 -0500 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2AE1C061575 for ; Wed, 13 Jan 2021 19:33:28 -0800 (PST) Received: by mail-pg1-x530.google.com with SMTP id c22so2823163pgg.13 for ; Wed, 13 Jan 2021 19:33:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=M5N5hogdb1VE5N+GuBnvP2hTDvEwQA42F7hxBNyZMt4=; b=FEqCHqMKatXUgxZo1m9x9XWMmJmnZLrMOpBLIkbng24V512Il3r0ZQNAi5YHI/s2R1 jau3yFgUJELL5UKibd7Q+RdwJfmPO6VUTfxHGI1Fvo3b+OXTuqIXNOKJ9EuXHdWcpsfP Z56E1Z56qn5TiRUlQPzBOzUmZlpSLF9suPKq54/u2GWIMt6H5b/3wla+uMVvIU6MUs2N RhYeiH4AADdHT+10avtmDmWydRpeILPcsagg4Dh7RPBLV5kR0KnjmzyBt1eyMABFzrq6 4Q0IpMrPCVk9hdMawRcOc1y7AaS3gQtK4BSbUAZzVimkJYuwmS2xjK5oW7wu4y5RUAkN QmqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=M5N5hogdb1VE5N+GuBnvP2hTDvEwQA42F7hxBNyZMt4=; b=FD6FE/G8RLqTRwZTUnYuLjQPbBfcfh+9eVLanTp0d00nbAKIRLVTXkeerXA4rs2r30 7NRxh9HxNhFiXyPCdYdxuIxTh4cW2Uh4MlnocdeLSjOMcbLl76OcmR7jY5G2h4yK3EzN z3tCZaOSeqwIjmqdHVaUv+/yc08X5nkMJEFopLe/NWv8O6tmHfNj3d13wTOieUHGZpux i4az17lChKdk4cqofNlAKGWYCsyzHCLR7e66/jANChHe2xrgLKK/cJs2NFnb73dkXXlF V48NXvwAkICt4Gv24Ujd0iENtmWY5AuTPkrMUCLdRHvXhCRcbXCYiOKADpNlC5r24e51 nX2g== X-Gm-Message-State: AOAM5330aor080oLb33IU+0of1Bz66SHPIytNQ82Jadz2ZOO0TBlL9mL YkS+LwzEYdnOd23kdVtEjKg= X-Google-Smtp-Source: ABdhPJwiK1AxhqNUts0GEcLWi4jomLrxuNv7CTGtOmpeAc78Pv+9YmYaaJopyRQaoE1OdGlIACQ6og== X-Received: by 2002:a63:f512:: with SMTP id w18mr5354005pgh.154.1610595208352; Wed, 13 Jan 2021 19:33:28 -0800 (PST) Received: from localhost ([100.87.84.221]) by smtp.gmail.com with ESMTPSA id o129sm3611513pfg.66.2021.01.13.19.33.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Jan 2021 19:33:27 -0800 (PST) Date: Thu, 14 Jan 2021 12:33:10 +0900 From: Sergey Senozhatsky To: Andrew Morton Cc: Hugh Dickins , "Kirill A. Shutemov" , Suleiman Souhlal , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: madvise(MADV_REMOVE) deadlocks on shmem THP Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, We are running into lockups during the memory pressure tests on our boards, which essentially NMI panic them. In short the test case is - THP shmem echo advise > /sys/kernel/mm/transparent_hugepage/shmem_enabled - And a user-space process doing madvise(MADV_HUGEPAGE) on new mappings, and madvise(MADV_REMOVE) when it wants to remove the page range The problem boils down to the reverse locking chain: kswapd does lock_page(page) -> down_read(page->mapping->i_mmap_rwsem) madvise() process does down_write(page->mapping->i_mmap_rwsem) -> lock_page(page) CPU0 CPU1 kswapd vfs_fallocate() shrink_node() shmem_fallocate() shrink_active_list() unmap_mapping_range() page_referenced() << lock page:PG_locked >> unmap_mapping_pages() << down_write(mapping->i_mmap_rwsem) >> rmap_walk_file() zap_page_range_single() down_read(mapping->i_mmap_rwsem) << W-locked on CPU1>> unmap_page_range() rwsem_down_read_failed() __split_huge_pmd() __rwsem_down_read_failed_common() __lock_page() << PG_locked on CPU0 >> schedule() wait_on_page_bit_common() io_schedule() -ss