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[23.128.96.18]) by mx.google.com with ESMTP id dd21si2992969edb.45.2021.04.22.13.37.00; Thu, 22 Apr 2021 13:37:24 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=TcMfLho5; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236949AbhDVUep (ORCPT + 99 others); Thu, 22 Apr 2021 16:34:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46800 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236851AbhDVUep (ORCPT ); Thu, 22 Apr 2021 16:34:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619123649; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=bPsR9zAvMT1rXu00S7RjYydgHJfjQUx3EMwYfq9HIMg=; b=TcMfLho5m38TIHVTYBOXxyy+xXPCqiyBVDELfsR0fxA+f1X80I8RuUettw3e6JJGcK9rbk TQTPYSCwSFbN4j1bCUniSnA83FEIWcUb/tarQtOXuZhW6EqGYUOnyEfapzDa7VEkwhDnJF pyKDObpLHToGxOMCXQ9SjJ/zsBhjqWQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-516-x7oK4LyIMbOEnxlHSgLzJA-1; Thu, 22 Apr 2021 16:34:05 -0400 X-MC-Unique: x7oK4LyIMbOEnxlHSgLzJA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BBAD4343A2; Thu, 22 Apr 2021 20:34:02 +0000 (UTC) Received: from optiplex-fbsd (unknown [10.3.128.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E5CFD60C17; Thu, 22 Apr 2021 20:33:58 +0000 (UTC) Date: Thu, 22 Apr 2021 16:33:56 -0400 From: Rafael Aquini To: chukaiping Cc: mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com, akpm@linux-foundation.org, vbabka@suse.cz, nigupta@nvidia.com, bhe@redhat.com, khalid.aziz@oracle.com, iamjoonsoo.kim@lge.com, mateusznosek0@gmail.com, sh_def@163.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2] mm/compaction:let proactive compaction order configurable Message-ID: References: <1618989713-20962-1-git-send-email-chukaiping@baidu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1618989713-20962-1-git-send-email-chukaiping@baidu.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 21, 2021 at 03:21:53PM +0800, chukaiping wrote: > Currently the proactive compaction order is fixed to > COMPACTION_HPAGE_ORDER(9), it's OK in most machines with lots of > normal 4KB memory, but it's too high for the machines with small > normal memory, for example the machines with most memory configured > as 1GB hugetlbfs huge pages. In these machines the max order of > free pages is often below 9, and it's always below 9 even with hard > compaction. This will lead to proactive compaction be triggered very > frequently. In these machines we only care about order of 3 or 4. > This patch export the oder to proc and let it configurable > by user, and the default value is still COMPACTION_HPAGE_ORDER. > > Signed-off-by: chukaiping > Reported-by: kernel test robot > --- > > Changes in v2: > - fix the compile error in ia64 and powerpc > - change the hard coded max order number from 10 to MAX_ORDER - 1 > > include/linux/compaction.h | 1 + > kernel/sysctl.c | 11 +++++++++++ > mm/compaction.c | 14 +++++++++++--- > 3 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/include/linux/compaction.h b/include/linux/compaction.h > index ed4070e..151ccd1 100644 > --- a/include/linux/compaction.h > +++ b/include/linux/compaction.h > @@ -83,6 +83,7 @@ static inline unsigned long compact_gap(unsigned int order) > #ifdef CONFIG_COMPACTION > extern int sysctl_compact_memory; > extern unsigned int sysctl_compaction_proactiveness; > +extern unsigned int sysctl_compaction_order; > extern int sysctl_compaction_handler(struct ctl_table *table, int write, > void *buffer, size_t *length, loff_t *ppos); > extern int sysctl_extfrag_threshold; > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 62fbd09..a607d4d 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -195,6 +195,8 @@ enum sysctl_writes_mode { > #endif /* CONFIG_SMP */ > #endif /* CONFIG_SCHED_DEBUG */ > > +static int max_buddy_zone = MAX_ORDER - 1; > + This should go into the #ifdef CONFIG_COMPACTION section below > #ifdef CONFIG_COMPACTION > static int min_extfrag_threshold; > static int max_extfrag_threshold = 1000; > @@ -2871,6 +2873,15 @@ int proc_do_static_key(struct ctl_table *table, int write, > .extra2 = &one_hundred, > }, > { > + .procname = "compaction_order", > + .data = &sysctl_compaction_order, > + .maxlen = sizeof(sysctl_compaction_order), > + .mode = 0644, > + .proc_handler = proc_dointvec_minmax, > + .extra1 = SYSCTL_ZERO, > + .extra2 = &max_buddy_zone, > + }, > + { > .procname = "extfrag_threshold", > .data = &sysctl_extfrag_threshold, > .maxlen = sizeof(int), > diff --git a/mm/compaction.c b/mm/compaction.c > index e04f447..bfd1d5e 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1925,16 +1925,16 @@ static bool kswapd_is_running(pg_data_t *pgdat) > > /* > * A zone's fragmentation score is the external fragmentation wrt to the > - * COMPACTION_HPAGE_ORDER. It returns a value in the range [0, 100]. > + * sysctl_compaction_order. It returns a value in the range [0, 100]. > */ > static unsigned int fragmentation_score_zone(struct zone *zone) > { > - return extfrag_for_order(zone, COMPACTION_HPAGE_ORDER); > + return extfrag_for_order(zone, sysctl_compaction_order); > } > > /* > * A weighted zone's fragmentation score is the external fragmentation > - * wrt to the COMPACTION_HPAGE_ORDER scaled by the zone's size. It > + * wrt to the sysctl_compaction_order scaled by the zone's size. It > * returns a value in the range [0, 100]. > * > * The scaling factor ensures that proactive compaction focuses on larger > @@ -2666,6 +2666,7 @@ static void compact_nodes(void) > * background. It takes values in the range [0, 100]. > */ > unsigned int __read_mostly sysctl_compaction_proactiveness = 20; > +unsigned int __read_mostly sysctl_compaction_order; > > /* > * This is the entry point for compacting all nodes via > @@ -2958,6 +2959,13 @@ static int __init kcompactd_init(void) > int nid; > int ret; > > + /* > + * move the initialization of sysctl_compaction_order to here to > + * eliminate compile error in ia64 and powerpc architecture because > + * COMPACTION_HPAGE_ORDER is a variable in this architecture > + */ This comment block belongs to your commit log, instead. Cheers, -- Rafael > + sysctl_compaction_order = COMPACTION_HPAGE_ORDER; > + > ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, > "mm/compaction:online", > kcompactd_cpu_online, NULL); > -- > 1.7.1 > >