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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 AA604CA9EC4 for ; Tue, 29 Oct 2019 21:02:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6974221734 for ; Tue, 29 Oct 2019 21:02:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="NwwDI9pw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6974221734 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 DF4716B0005; Tue, 29 Oct 2019 17:02:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DA48C6B0006; Tue, 29 Oct 2019 17:02:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C944E6B0007; Tue, 29 Oct 2019 17:02:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id A9B9F6B0005 for ; Tue, 29 Oct 2019 17:02:12 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 4C5256C21 for ; Tue, 29 Oct 2019 21:02:12 +0000 (UTC) X-FDA: 76098044904.10.sort64_879a4181da20d X-HE-Tag: sort64_879a4181da20d X-Filterd-Recvd-Size: 4467 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf39.hostedemail.com (Postfix) with ESMTP for ; Tue, 29 Oct 2019 21:02:11 +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 199182087E; Tue, 29 Oct 2019 21:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572382930; bh=DU276rBOmXNq/UGPWSsHr+vCt4tZPq33yvckroogy+s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=NwwDI9pwnDo75NGmhbNfHM/Z52BOv/JUemoHekwTJypzHNtZFbJvRDk+E1Wc7jgUC On20wb4dVGoVudHP0YtkioHoHAmgGvETr9xPwj0hBuoBho6V+6x/fFUAFlnWfQN9Vw pFqgMOSZ0/b9dD4OKeTBUpNaSAK7B84JMq1Kn71U= Date: Tue, 29 Oct 2019 14:02:09 -0700 From: Andrew Morton To: Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= 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: khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Message-Id: <20191029140209.e70385637d3617ad43869f31@linux-foundation.org> In-Reply-To: <20191029201513.GG1208@intel.com> References: <20191029201513.GG1208@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 22:15:13 +0200 Ville Syrj=E4l=E4 wrote: > Hi, >=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(). >=20 > My naive idea would be to just reorder those things, but not sure > if there's some magic ordering constraint here. At least the machine > still boots when I do it :) >=20 > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 0a1b4b484ac5..f05d27b7183d 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_struct *= mm, > =20 > anon_vma_lock_write(vma->anon_vma); > =20 > - pte =3D pte_offset_map(pmd, address); > - pte_ptl =3D pte_lockptr(mm, pmd); > - > mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm, > address, address + HPAGE_PMD_SIZE); > mmu_notifier_invalidate_range_start(&range); > + > + pte =3D pte_offset_map(pmd, address); > + pte_ptl =3D pte_lockptr(mm, pmd); > + > pmd_ptl =3D pmd_lock(mm, pmd); /* probably unnecessary */ > /* > * After this gup_fast can't run anymore. This also removes >=20 Looks good to me. Can you resend it with a signoff please?