From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by kanga.kvack.org (Postfix) with ESMTP id BA1068E0001 for ; Thu, 27 Dec 2018 11:44:56 -0500 (EST) Received: by mail-pg1-f198.google.com with SMTP id 202so17950545pgb.6 for ; Thu, 27 Dec 2018 08:44:56 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id h19si33219281pgb.231.2018.12.27.08.44.55 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 27 Dec 2018 08:44:55 -0800 (PST) Subject: Re: [PATCH] mm: compaction.c: Propagate return value upstream References: <20181226194257.11038-1-pakki001@umn.edu> <20181227035029.GE20878@bombadil.infradead.org> From: Randy Dunlap Message-ID: <6af3b9ee-34c9-ba6d-f4c0-2c8e21b0550e@infradead.org> Date: Thu, 27 Dec 2018 08:44:45 -0800 MIME-Version: 1.0 In-Reply-To: <20181227035029.GE20878@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox , Aditya Pakki Cc: kjlu@umn.edu, Andrew Morton , Michal Hocko , Vlastimil Babka , Joonsoo Kim , David Rientjes , Yang Shi , Johannes Weiner , Joe Perches , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman On 12/26/18 7:50 PM, Matthew Wilcox wrote: > On Wed, Dec 26, 2018 at 01:42:56PM -0600, Aditya Pakki wrote: >> In sysctl_extfrag_handler(), proc_dointvec_minmax() can return an >> error. The fix propagates the error upstream in case of failure. > > Why not just ... Yes, this change (below) makes sense to me. > Mel, Randy? You seem to have been the prime instigators on this. I expect that all I did was move the location of the source code lines of the sysctl, but that is just a guess, based on this commit message: [randy.dunlap@oracle.com: Fix build errors when proc fs is not configured] > diff --git a/include/linux/compaction.h b/include/linux/compaction.h > index 68250a57aace..70d0256edd31 100644 > --- a/include/linux/compaction.h > +++ b/include/linux/compaction.h > @@ -88,8 +88,6 @@ extern int sysctl_compact_memory; > extern int sysctl_compaction_handler(struct ctl_table *table, int write, > void __user *buffer, size_t *length, loff_t *ppos); > extern int sysctl_extfrag_threshold; > -extern int sysctl_extfrag_handler(struct ctl_table *table, int write, > - void __user *buffer, size_t *length, loff_t *ppos); > extern int sysctl_compact_unevictable_allowed; > > extern int fragmentation_index(struct zone *zone, unsigned int order); > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 5fc724e4e454..e9c69247fc29 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1439,7 +1439,7 @@ static struct ctl_table vm_table[] = { > .data = &sysctl_extfrag_threshold, > .maxlen = sizeof(int), > .mode = 0644, > - .proc_handler = sysctl_extfrag_handler, > + .proc_handler = proc_dointvec_minmax, > .extra1 = &min_extfrag_threshold, > .extra2 = &max_extfrag_threshold, > }, > diff --git a/mm/compaction.c b/mm/compaction.c > index 7c607479de4a..80b941d9b6e7 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1876,14 +1876,6 @@ int sysctl_compaction_handler(struct ctl_table *table, int write, > return 0; > } > > -int sysctl_extfrag_handler(struct ctl_table *table, int write, > - void __user *buffer, size_t *length, loff_t *ppos) > -{ > - proc_dointvec_minmax(table, write, buffer, length, ppos); > - > - return 0; > -} > - > #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) > static ssize_t sysfs_compact_node(struct device *dev, > struct device_attribute *attr, > -- ~Randy