From patchwork Thu Jun 4 17:18:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 224818 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, 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 BFE8DC433DF for ; Thu, 4 Jun 2020 17:18:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E7E1208B8 for ; Thu, 4 Jun 2020 17:18:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591291111; bh=uw9ajEZK2U3R/mzyqBwWkfseWaLTMdFVYUrHwtUw4+E=; h=Date:From:To:Subject:List-ID:From; b=JHNGgCTuElPselTkM3gRS6AF+3cYvogiGzWOEzDGKyMAUfPYXulgWAMrSvLWqjWxj TlS5vYOfNUXNwV1IdQyD574TCe9Ct2yex4l2uanAI50S5eeKmTG6ZHek62tYt+Cpoz ScZwRFY5xksWak7YKaiwuWvRJw6rMcibdf2sCMsE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730123AbgFDRSb (ORCPT ); Thu, 4 Jun 2020 13:18:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:40084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730088AbgFDRSa (ORCPT ); Thu, 4 Jun 2020 13:18:30 -0400 Received: from localhost.localdomain (c-71-198-47-131.hsd1.ca.comcast.net [71.198.47.131]) (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 B2EDB208A7; Thu, 4 Jun 2020 17:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591291110; bh=uw9ajEZK2U3R/mzyqBwWkfseWaLTMdFVYUrHwtUw4+E=; h=Date:From:To:Subject:From; b=JADrRbd+tHXXwLx+jZV4vrvb5O9yD71MgwceUyOOsAcqSXNt7SIPZBOxq0gGK9dBr N702xj1zeWnzn2rYkKxGa02UdxjM1iayMNxLlAT5RDJp9BewtBljYALkdl18YhfXE6 +KBEtV6++frFgSn32dmbbOQMA7Y/j5pTA8fCt/xA= Date: Thu, 04 Jun 2020 10:18:29 -0700 From: akpm@linux-foundation.org To: dan.j.williams@intel.com, daniel.m.jordan@oracle.com, david@redhat.com, jmorris@namei.org, ktkhai@virtuozzo.com, mhocko@suse.com, mm-commits@vger.kernel.org, pankaj.gupta.linux@gmail.com, pasha.tatashin@soleen.com, sashal@kernel.org, shile.zhang@linux.alibaba.com, stable@vger.kernel.org, vbabka@suse.cz, yiwei@redhat.com Subject: [merged] mm-call-cond_resched-from-deferred_init_memmap.patch removed from -mm tree Message-ID: <20200604171829.2a2P11QAF%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm: call cond_resched() from deferred_init_memmap() has been removed from the -mm tree. Its filename was mm-call-cond_resched-from-deferred_init_memmap.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Pavel Tatashin Subject: mm: call cond_resched() from deferred_init_memmap() 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 Link: http://lkml.kernel.org/r/20200403140952.17177-4-pasha.tatashin@soleen.com Fixes: 3a2d7fa8a3d5 ("mm: disable interrupts while initializing deferred pages") Reported-by: Yiqian Wei Tested-by: David Hildenbrand Signed-off-by: Pavel Tatashin Reviewed-by: Daniel Jordan Acked-by: Michal Hocko Reviewed-by: David Hildenbrand Reviewed-by: Pankaj Gupta Cc: Dan Williams Cc: James Morris Cc: Kirill Tkhai Cc: Sasha Levin Cc: Shile Zhang Cc: Vlastimil Babka Cc: [4.17+] Signed-off-by: Andrew Morton --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c~mm-call-cond_resched-from-deferred_init_memmap +++ a/mm/page_alloc.c @@ -1870,7 +1870,7 @@ 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 */