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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2AC27C433E1 for ; Fri, 19 Jun 2020 15:12:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C2F221D79 for ; Fri, 19 Jun 2020 15:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579552; bh=cvCCuzGgzekYEp4uFZFh7Ce/oDkDgI8R02t/H7jwM3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cIF2tbjYhv9CVzGgYP1HNdXH65YPgXck9xfKtIsBzH0WAhjiTBj76J9d0+FiFz+p2 PNukYfxabdtXnX3111vFx7abUlxO0x5ci0lPyc+xkgHC6/pjw4WmFYPbhpj7NwctZH x4T9JuPwwKdPXPJ1xPMIx6WpjNpv6ClOt47Fk9eg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403907AbgFSPMb (ORCPT ); Fri, 19 Jun 2020 11:12:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:42766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391574AbgFSPMU (ORCPT ); Fri, 19 Jun 2020 11:12:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 6629E218AC; Fri, 19 Jun 2020 15:12:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579538; bh=cvCCuzGgzekYEp4uFZFh7Ce/oDkDgI8R02t/H7jwM3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2qTzOHAqdKYUojuHogKjSUZmBKoBzKcP2U/kNTCrN5T+cKWO8ypbpZ0WEFiSQ5jKH 0R/KBsQyBSZeSLZDch+RmgpKbIvURtmRn+/gs9SI2QjLDhO7BbyWDgC5DRCHIEM7R7 +dVAlU9PHZDhnKJUnMxuak8gHSHwp5TdoSzKGmBk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yiqian Wei , Pavel Tatashin , Andrew Morton , David Hildenbrand , Daniel Jordan , Pankaj Gupta , Michal Hocko , Dan Williams , James Morris , Kirill Tkhai , Sasha Levin , Shile Zhang , Vlastimil Babka , Linus Torvalds Subject: [PATCH 5.4 173/261] mm: call cond_resched() from deferred_init_memmap() Date: Fri, 19 Jun 2020 16:33:04 +0200 Message-Id: <20200619141658.207376407@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141649.878808811@linuxfoundation.org> References: <20200619141649.878808811@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Tatashin commit da97f2d56bbd880b4138916a7ef96f9881a551b2 upstream. Now that deferred pages are initialized with interrupts enabled we can replace touch_nmi_watchdog() with cond_resched(), as it was before 3a2d7fa8a3d5. For now, we cannot do the same in deferred_grow_zone() as it is still initializes pages with interrupts disabled. This change fixes RCU problem described in https://lkml.kernel.org/r/20200401104156.11564-2-david@redhat.com [ 60.474005] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 60.475000] rcu: 1-...0: (0 ticks this GP) idle=02a/1/0x4000000000000000 softirq=1/1 fqs=15000 [ 60.475000] rcu: (detected by 0, t=60002 jiffies, g=-1199, q=1) [ 60.475000] Sending NMI from CPU 0 to CPUs 1: [ 1.760091] NMI backtrace for cpu 1 [ 1.760091] CPU: 1 PID: 20 Comm: pgdatinit0 Not tainted 4.18.0-147.9.1.el8_1.x86_64 #1 [ 1.760091] Hardware name: Red Hat KVM, BIOS 1.13.0-1.module+el8.2.0+5520+4e5817f3 04/01/2014 [ 1.760091] RIP: 0010:__init_single_page.isra.65+0x10/0x4f [ 1.760091] Code: 48 83 cf 63 48 89 f8 0f 1f 40 00 48 89 c6 48 89 d7 e8 6b 18 80 ff 66 90 5b c3 31 c0 b9 10 00 00 00 49 89 f8 48 c1 e6 33 f3 ab 07 00 00 00 48 c1 e2 36 41 c7 40 34 01 00 00 00 48 c1 e0 33 41 [ 1.760091] RSP: 0000:ffffba783123be40 EFLAGS: 00000006 [ 1.760091] RAX: 0000000000000000 RBX: fffffad34405e300 RCX: 0000000000000000 [ 1.760091] RDX: 0000000000000000 RSI: 0010000000000000 RDI: fffffad34405e340 [ 1.760091] RBP: 0000000033f3177e R08: fffffad34405e300 R09: 0000000000000002 [ 1.760091] R10: 000000000000002b R11: ffff98afb691a500 R12: 0000000000000002 [ 1.760091] R13: 0000000000000000 R14: 000000003f03ea00 R15: 000000003e10178c [ 1.760091] FS: 0000000000000000(0000) GS:ffff9c9ebeb00000(0000) knlGS:0000000000000000 [ 1.760091] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.760091] CR2: 00000000ffffffff CR3: 000000a1cf20a001 CR4: 00000000003606e0 [ 1.760091] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.760091] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1.760091] Call Trace: [ 1.760091] deferred_init_pages+0x8f/0xbf [ 1.760091] deferred_init_memmap+0x184/0x29d [ 1.760091] ? deferred_free_pages.isra.97+0xba/0xba [ 1.760091] kthread+0x112/0x130 [ 1.760091] ? kthread_flush_work_fn+0x10/0x10 [ 1.760091] ret_from_fork+0x35/0x40 [ 89.123011] node 0 initialised, 1055935372 pages in 88650ms Fixes: 3a2d7fa8a3d5 ("mm: disable interrupts while initializing deferred pages") Reported-by: Yiqian Wei Signed-off-by: Pavel Tatashin Signed-off-by: Andrew Morton Tested-by: David Hildenbrand Reviewed-by: Daniel Jordan Reviewed-by: David Hildenbrand Reviewed-by: Pankaj Gupta Acked-by: Michal Hocko Cc: Dan Williams Cc: James Morris Cc: Kirill Tkhai Cc: Sasha Levin Cc: Shile Zhang Cc: Vlastimil Babka Cc: [4.17+] Link: http://lkml.kernel.org/r/20200403140952.17177-4-pasha.tatashin@soleen.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1817,7 +1817,7 @@ static int __init deferred_init_memmap(v */ while (spfn < epfn) { nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn); - touch_nmi_watchdog(); + cond_resched(); } zone_empty: /* Sanity check that the next zone really is unpopulated */