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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 23921CA9EC3 for ; Tue, 29 Oct 2019 21:43:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D93A421479 for ; Tue, 29 Oct 2019 21:43:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="VszNvjPD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D93A421479 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6AB156B0007; Tue, 29 Oct 2019 17:43:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 65A3E6B0008; Tue, 29 Oct 2019 17:43:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 548336B000A; Tue, 29 Oct 2019 17:43:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id 2D1A26B0007 for ; Tue, 29 Oct 2019 17:43:04 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id C9159824999B for ; Tue, 29 Oct 2019 21:43:03 +0000 (UTC) X-FDA: 76098147846.25.join55_37c96a6c1e202 X-HE-Tag: join55_37c96a6c1e202 X-Filterd-Recvd-Size: 3852 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 29 Oct 2019 21:43:03 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CA86420717; Tue, 29 Oct 2019 21:43:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572385382; bh=Y0G509BJm+yUUQOdD74mNDRT351ZkhaUs2G/wLyvPt8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VszNvjPDVLpbwpHef9kVv6cX6abIk/GOjL1tztsbGBbPgHmUSOyNvOuGudxchQymo /JxicG6Pxh0AqtIi6l3VurnFM6B+qd1oRnt7v0cgxlVwDu86EzZntFagmwDAfsPpC+ sxs2GxE0au8V5xpnn5exTG+HQY/qrayPCgAQfL4A= Date: Tue, 29 Oct 2019 14:43:00 -0700 From: Andrew Morton To: Ville Syrjala Cc: linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-mm@kvack.org, =?ISO-8859-1?Q?J=E9?= =?ISO-8859-1?Q?r=F4me?= Glisse , Ralph Campbell , Ira Weiny , Jason Gunthorpe , Daniel Vetter , Andrea Arcangeli Subject: Re: [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Message-Id: <20191029144300.160811015055490f042975d6@linux-foundation.org> In-Reply-To: <20191029212513.23566-1-ville.syrjala@linux.intel.com> References: <20191029140209.e70385637d3617ad43869f31@linux-foundation.org> <20191029212513.23566-1-ville.syrjala@linux.intel.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 29 Oct 2019 23:25:13 +0200 Ville Syrjala wrote: > From: Ville Syrj=E4l=E4 >=20 > I got some khugepaged spew on a 32bit x86: >=20 > [ 217.490026] BUG: sleeping function called from invalid context at incl= ude/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 220= 3 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 >=20 > Looks like it's due to CONFIG_HIGHPTE=3Dy pte_offset_map()->kmap_atomic() > vs. mmu_notifier_invalidate_range_start(). Let's do the naive approach > and just reorder the two operations. Thanks. I'll add=20 Fixes: 810e24e009cf71 ("mm/mmu_notifiers: annotate with might_sleep()") Cc: although 810e24e009cf71 merely exposed the bug.