From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 560804405C6 for ; Thu, 16 Feb 2017 01:23:31 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id e4so12339580pfg.4 for ; Wed, 15 Feb 2017 22:23:31 -0800 (PST) Received: from out4439.biz.mail.alibaba.com (out4439.biz.mail.alibaba.com. [47.88.44.39]) by mx.google.com with ESMTP id k195si2090459pga.230.2017.02.15.22.23.29 for ; Wed, 15 Feb 2017 22:23:30 -0800 (PST) Reply-To: "Hillf Danton" From: "Hillf Danton" References: <20170215092247.15989-1-mgorman@techsingularity.net> <20170215092247.15989-4-mgorman@techsingularity.net> In-Reply-To: <20170215092247.15989-4-mgorman@techsingularity.net> Subject: Re: [PATCH 3/3] mm, vmscan: Prevent kswapd sleeping prematurely due to mismatched classzone_idx Date: Thu, 16 Feb 2017 14:23:08 +0800 Message-ID: <001501d2881d$242aa790$6c7ff6b0$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Language: zh-cn Sender: owner-linux-mm@kvack.org List-ID: To: 'Mel Gorman' , 'Andrew Morton' Cc: 'Shantanu Goel' , 'Chris Mason' , 'Johannes Weiner' , 'Vlastimil Babka' , 'LKML' , 'Linux-MM' On February 15, 2017 5:23 PM Mel Gorman wrote: > */ > static int kswapd(void *p) > { > - unsigned int alloc_order, reclaim_order, classzone_idx; > + unsigned int alloc_order, reclaim_order; > + unsigned int classzone_idx = MAX_NR_ZONES - 1; > pg_data_t *pgdat = (pg_data_t*)p; > struct task_struct *tsk = current; > > @@ -3447,20 +3466,23 @@ static int kswapd(void *p) > tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD; > set_freezable(); > > - pgdat->kswapd_order = alloc_order = reclaim_order = 0; > - pgdat->kswapd_classzone_idx = classzone_idx = 0; > + pgdat->kswapd_order = 0; > + pgdat->kswapd_classzone_idx = MAX_NR_ZONES; > for ( ; ; ) { > bool ret; > > + alloc_order = reclaim_order = pgdat->kswapd_order; > + classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx); > + > kswapd_try_sleep: > kswapd_try_to_sleep(pgdat, alloc_order, reclaim_order, > classzone_idx); > > /* Read the new order and classzone_idx */ > alloc_order = reclaim_order = pgdat->kswapd_order; > - classzone_idx = pgdat->kswapd_classzone_idx; > + classzone_idx = kswapd_classzone_idx(pgdat, 0); > pgdat->kswapd_order = 0; > - pgdat->kswapd_classzone_idx = 0; > + pgdat->kswapd_classzone_idx = MAX_NR_ZONES; > > ret = try_to_freeze(); > if (kthread_should_stop()) > @@ -3486,9 +3508,6 @@ static int kswapd(void *p) > reclaim_order = balance_pgdat(pgdat, alloc_order, classzone_idx); > if (reclaim_order < alloc_order) > goto kswapd_try_sleep; If we fail order-5 request, can we then give up order-5, and try order-3 if requested, after napping? > - > - alloc_order = reclaim_order = pgdat->kswapd_order; > - classzone_idx = pgdat->kswapd_classzone_idx; > } > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org