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=-5.2 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,USER_AGENT_SANE_1 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 C8318CA9EAF for ; Wed, 30 Oct 2019 07:08:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A063F20874 for ; Wed, 30 Oct 2019 07:08:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="lOZ9swOk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727345AbfJ3HIV (ORCPT ); Wed, 30 Oct 2019 03:08:21 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:37450 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727321AbfJ3HIU (ORCPT ); Wed, 30 Oct 2019 03:08:20 -0400 Received: by mail-lj1-f196.google.com with SMTP id v2so1405883lji.4 for ; Wed, 30 Oct 2019 00:08:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=YkfgFeV4FsqY1VHKqgXeZNImOvIVbyPpJ+xeXvIsYXA=; b=lOZ9swOkTxzq0Xy7OhmKpjX25Jx0xlgBUxBj5a6FSJlFEhL4Io9YbZZxHcmTkj5HM5 T6g9ScBLH1q7B+b4qUfuSWipUL6goM/wPyO4g8bLnsQ5OOOs4fDzU2NGHu8xxfCFvSx8 DLb4aHcs2bFD1zMZNMLCD1k28sLyzGgTQMsrosXCrzCT8JaO0dR0f4Yxn0/yGGk47a/J N3oovJgOsiCypPD9aW5VfGk5JqrHrKcaWXlV8bLDC2xXzdwLikiGIrfe6MmsQgriPkKK WeODFxLW8v5o8mSlGx6HAyGs6NEScGGSI+QGWS40isZ+lpYzEqHJHm1B//wIyyJYSgnh kfdQ== 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:content-transfer-encoding :in-reply-to:user-agent; bh=YkfgFeV4FsqY1VHKqgXeZNImOvIVbyPpJ+xeXvIsYXA=; b=KAJ9UlqNQWkkhJ2Vn/C5Z7ixConfXsp8xai4XFaQCYlnweykCYrDNxhOO2ow04nzAw s6olIx2PRa3BMgw7omHfE+fHOZoceS9K/PmDi8Iqk4Yr9zel4rmpmxZaozJe4VInHnpV 4XHwlGl7/i//cQhyHbpnDPOF6Q4rw1JGWTnUnrK1vdvhTIsGbVSkyYyzhqrARBc9y3FN EZ4OBY3uVnfKhx+aVBVfrhZbFRiC/CeLwJgrLA3/mI79L5LGS0EjutK/0EnPqtIGnAGH G4qPeRF3HtLed0pDvxDME7rROWMAw1QFWSL4i1iiPYI01r+cxyYQaJvTLjQaQ2GWKlAT OCSA== X-Gm-Message-State: APjAAAXsPxuJKQxgaHw5mwsTu9TQX4GitY7yPaanCa2A0eAyeLGpnsYC +ahiDKk86ovVyvoqKqcZ6uN1mA== X-Google-Smtp-Source: APXvYqysVS8kahgG2FSdDRKL/fz1eoa8EMMKPRm3Jh8/IaKIVk9RLkhHTfAGnTrRvreuq8KK4j48yA== X-Received: by 2002:a2e:3919:: with SMTP id g25mr5379568lja.162.1572419297242; Wed, 30 Oct 2019 00:08:17 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id m3sm741816lfl.0.2019.10.30.00.08.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Oct 2019 00:08:16 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id D03661003C9; Wed, 30 Oct 2019 10:08:15 +0300 (+03) Date: Wed, 30 Oct 2019 10:08:15 +0300 From: "Kirill A. Shutemov" To: Ville Syrjala Cc: linux-kernel@vger.kernel.org, Andrew Morton , "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-mm@kvack.org Subject: Re: [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Message-ID: <20191030070815.y4ggbbi5bd4wksbr@box> References: <20191029140209.e70385637d3617ad43869f31@linux-foundation.org> <20191029212513.23566-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191029212513.23566-1-ville.syrjala@linux.intel.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 29, 2019 at 11:25:13PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä > > I got some khugepaged spew on a 32bit x86: > > [ 217.490026] BUG: sleeping function called from invalid context at include/linux/mmu_notifier.h:346 > [ 217.492826] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 25, name: khugepaged > [ 217.495589] INFO: lockdep is turned off. > [ 217.498371] CPU: 1 PID: 25 Comm: khugepaged Not tainted 5.4.0-rc5-elk+ #206 > [ 217.501233] Hardware name: System manufacturer P5Q-EM/P5Q-EM, BIOS 2203 07/08/2009 > [ 217.501697] Call Trace: > [ 217.501697] dump_stack+0x66/0x8e > [ 217.501697] ___might_sleep.cold.96+0x95/0xa6 > [ 217.501697] __might_sleep+0x2e/0x80 > [ 217.501697] collapse_huge_page.isra.51+0x5ac/0x1360 > [ 217.501697] ? __alloc_pages_nodemask+0xec/0xf80 > [ 217.501697] ? __alloc_pages_nodemask+0x191/0xf80 > [ 217.501697] ? trace_hardirqs_on+0x4a/0xf0 > [ 217.501697] khugepaged+0x9a9/0x20f0 > [ 217.501697] ? _raw_spin_unlock+0x21/0x30 > [ 217.501697] ? trace_hardirqs_on+0x4a/0xf0 > [ 217.501697] ? wait_woken+0xa0/0xa0 > [ 217.501697] kthread+0xf5/0x110 > [ 217.501697] ? collapse_pte_mapped_thp+0x3b0/0x3b0 > [ 217.501697] ? kthread_create_worker_on_cpu+0x20/0x20 > [ 217.501697] ret_from_fork+0x2e/0x38 > > Looks like it's due to CONFIG_HIGHPTE=y pte_offset_map()->kmap_atomic() > vs. mmu_notifier_invalidate_range_start(). Let's do the naive approach > and just reorder the two operations. > > Cc: linux-kernel@vger.kernel.org > Cc: Andrew Morton > Cc: "Kirill A. Shutemov" > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: "H. Peter Anvin" > Cc: linux-mm@kvack.org > Signed-off-by: Ville Syrjälä Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov