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=-6.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 CF5F7C07E95 for ; Sat, 10 Jul 2021 18:46:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 618366139A for ; Sat, 10 Jul 2021 18:46:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 618366139A 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 2FCE26B0074; Sat, 10 Jul 2021 14:46:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2ACC86B0078; Sat, 10 Jul 2021 14:46:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1758E6B007B; Sat, 10 Jul 2021 14:46:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0116.hostedemail.com [216.40.44.116]) by kanga.kvack.org (Postfix) with ESMTP id E2BB26B0074 for ; Sat, 10 Jul 2021 14:46:18 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0A95722012 for ; Sat, 10 Jul 2021 18:46:18 +0000 (UTC) X-FDA: 78347558436.18.9EE5D86 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf07.hostedemail.com (Postfix) with ESMTP id 98C0310036B0 for ; Sat, 10 Jul 2021 18:46:17 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 8BD1D61279; Sat, 10 Jul 2021 18:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625942773; bh=ZjhoTSsw3XgjxOm9U7sZ17N78UcAMbUtdDRXWELDlCA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ldgkQ1kfk2K3tXkAdSjnjdRjwMaXgO2kxxWxHtR0v5uEmqvU5I/mIUZVOxGtz3j1h Xh682rpOcp6cVumqy9dRRytEaTH+ZM6pVMIO9TEGB+vNnwa82vY7nLHijXLQCu9/2b EqLKz/ZLBbHR7ILZUN8u7orZUyaemLYKCSPze/iI= Date: Sat, 10 Jul 2021 11:46:13 -0700 From: Andrew Morton To: qiang.zhang@windriver.com Cc: mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/page_alloc: avoid hard lockups in __alloc_pages_bulk() Message-Id: <20210710114613.0db3ac139a7b3102a6ca3ad4@linux-foundation.org> In-Reply-To: <20210710112929.232268-1-qiang.zhang@windriver.com> References: <20210710112929.232268-1-qiang.zhang@windriver.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ldgkQ1kf; spf=pass (imf07.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam02 X-Stat-Signature: p4uopgk99pfismyaciqqbmp5dqjp785j X-Rspamd-Queue-Id: 98C0310036B0 X-HE-Tag: 1625942777-810092 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 Sat, 10 Jul 2021 19:29:29 +0800 qiang.zhang@windriver.com wrote: > From: Zqiang > > The __alloc_pages_bulk() mainly used for batch allocation of > order-0 pages, in the case of holding pagesets.lock, if too > many pages are required, maybe trigger hard lockup watchdog. Ouch. Has this been observed in testing? If so, can you please share the kernel debug output from that event?