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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 F05D9C433E0 for ; Tue, 26 May 2020 16:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFF6F20721 for ; Tue, 26 May 2020 16:02:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="AZvUVlJq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730092AbgEZQCG (ORCPT ); Tue, 26 May 2020 12:02:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727862AbgEZQCF (ORCPT ); Tue, 26 May 2020 12:02:05 -0400 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C895C03E96D for ; Tue, 26 May 2020 09:02:05 -0700 (PDT) Received: by mail-qv1-xf43.google.com with SMTP id x13so9668226qvr.2 for ; Tue, 26 May 2020 09:02:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=RsZ3nQfGjW40v4ckRRp9241TQQ4YCE7GdfX8IPCvDyE=; b=AZvUVlJqEqbAPtDWEcV8xLSKNrSwwqm27o4j1nKpKyNIvP//3xF9TBUmSqeioWu+ox GgUtzLzzkJzvIbm87q0XvHko4QXlFaYxgKgfCZ53z4iBOhQnGqODmLbw626evo9klZtu c7PoTVabRQKKhf5nWGB1E7GcRx+eMZZcPz81NaE8FAVR20U3lqHBNcCpwjcPFS5ErJ+8 6XZEtI7fjLtnGewlpV2uHO14tWYN0wa4KnFXX+ibs43sGR8LaHz0R1Bm+9wCm93w5gpq u4epjiy5ZZpl+TZKm6frdFVstFQ04kgG6wE7yggabAskwiesK6ye0FxlnjiklEHIwV5l thfw== 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:references :mime-version:content-disposition:in-reply-to; bh=RsZ3nQfGjW40v4ckRRp9241TQQ4YCE7GdfX8IPCvDyE=; b=gXpwbrVPNr4jirEpv3g0nO+gVXWQUErh2r/p6eoUUE5soNrVtEEHcDMYfe9z45REo2 guNN9tbNzw5I6T+ieBlYdTnVWT4ogFMMghdYoWwkkaSrUUQ9JQfyjUG35fddSFWF/oFK NupIo8L/DIf9MPWQncgjDA2EomNJ0gh18FA9o3i/tQgZI4UBWb+mBjvRRicBu+hnmoP3 5ZPUnQgiNHGS+LnpERV1+T/qumupYnborcBTerbP4aT9b7BiqAoXVBm+g37uW6+bMwEv ceAmTi7Fwtes0Q0hmkH0Nv1J3mP23DajANOppXu3NAE2n3p/M7lT5mTTMBHp5GwwswMk xYVA== X-Gm-Message-State: AOAM531Pk5ZLZ6utjzWK0CbEqcRb+z21FYR9hHxfrSuv2B+84OAz+adA cDWF0fTB1aBWW3YUE+k8JWxyoA== X-Google-Smtp-Source: ABdhPJzhXcKDUYQ8+zI3NmJftxHzdTRDdvli5ewQjK6oPrSCn55dFt7LvsFzmcLbWioE/ZJdmqLuIA== X-Received: by 2002:a0c:b354:: with SMTP id a20mr20923201qvf.205.1590508924821; Tue, 26 May 2020 09:02:04 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:8152]) by smtp.gmail.com with ESMTPSA id q34sm58103qtd.89.2020.05.26.09.02.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 09:02:04 -0700 (PDT) Date: Tue, 26 May 2020 12:01:40 -0400 From: Johannes Weiner To: Hugh Dickins Cc: Andrew Morton , Song Liu , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm,thp: stop leaking unreleased file pages Message-ID: <20200526160140.GC850116@cmpxchg.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 23, 2020 at 06:50:15PM -0700, Hugh Dickins wrote: > When collapse_file() calls try_to_release_page(), it has already > isolated the page: so if releasing buffers happens to fail (as it > sometimes does), remember to putback_lru_page(): otherwise that page is > left unreclaimable and unfreeable, and the file extent uncollapsible. Oof, I could imagine that was painful to debug (unless you already suspected file THP due to a targeted test or similar). Kudos. > Signed-off-by: Hugh Dickins > Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") > Cc: stable@vger.kernel.org # v5.4+ Acked-by: Johannes Weiner