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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 31FE6C43331 for ; Thu, 26 Mar 2020 18:58:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03CC720714 for ; Thu, 26 Mar 2020 18:58:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="iNi3HDYc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728148AbgCZS6N (ORCPT ); Thu, 26 Mar 2020 14:58:13 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:35434 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725994AbgCZS6N (ORCPT ); Thu, 26 Mar 2020 14:58:13 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02QInG0x004620; Thu, 26 Mar 2020 18:58:05 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=6o5UWSo4SFsyev7vitT/qH8UlQgFN1m+GAnP6vmJrIE=; b=iNi3HDYczgmg/jvag0eBycnWWfMBzX8wja1UAaIlTfvACKJAKey3IhMPDJ8668sSyVxJ n6yqnq1kFX+Sr2S29E2ZIaGsdMKR0L52ilIz0KoQXvGqud+9WorV/bbdJcDTogHm/h0N VJkdztBjsqS9MAvE3I/Pzs9os4H4hps7Z8kRCYyDI4wbBMKIfRZ86o0RD04s3vkquo0D 1UMfzRvYBkP4TqSrZA9ujBkFzC6MSvEwBoSrshrksWYM9IkHNZpytJ91oJgJxSOyA0C8 Z2CYlaPa281phHtzENAqdczmwlOYUsauv1zFM5xFwRnxNNa0acxdR0s89GjyxvFkcZ0g CA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2ywabrhprg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Mar 2020 18:58:05 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02QIp4vH056829; Thu, 26 Mar 2020 18:58:05 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2yxw4u76jw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Mar 2020 18:58:05 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 02QIw320030108; Thu, 26 Mar 2020 18:58:03 GMT Received: from ca-dmjordan1.us.oracle.com (/10.211.9.48) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 26 Mar 2020 11:58:02 -0700 Date: Thu, 26 Mar 2020 14:58:22 -0400 From: Daniel Jordan To: Shile Zhang Cc: Andrew Morton , Kirill Tkhai , Pavel Tatashin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm: fix tick timer stall during deferred page init Message-ID: <20200326185822.6n56yl2llvdranur@ca-dmjordan1.us.oracle.com> References: <20200311123848.118638-1-shile.zhang@linux.alibaba.com> <20200319190512.cwnvgvv3upzcchkm@ca-dmjordan1.us.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200319190512.cwnvgvv3upzcchkm@ca-dmjordan1.us.oracle.com> User-Agent: NeoMutt/20180716 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9572 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=0 spamscore=0 mlxlogscore=999 adultscore=0 phishscore=0 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003260140 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9572 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 lowpriorityscore=0 malwarescore=0 phishscore=0 priorityscore=1501 clxscore=1015 adultscore=0 mlxscore=0 mlxlogscore=999 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003260140 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 19, 2020 at 03:05:12PM -0400, Daniel Jordan wrote: > Regardless, > Reviewed-by: Daniel Jordan Darn, I spoke too soon. On a two-socket Xeon, smaller values of TICK_PAGE_COUNT caused the deferred init timestamp to grow by over 25%. This was with pgdatinit0 bound to the timer interrupt CPU to make sure the issue always reproduces. TICK_PAGE_COUNT node 0 deferred init time (ms) --------------- --------------- 4096 610 8192 587 16384 487 32768 480 // used in the patch Instead of trying to find a constant that lets the timer interrupt run often enough, I think a better way forward is to reconsider how we handle the resize lock. I plan to prototype something and reply back with what I get.