Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752043Ab0BSAq7 (ORCPT ); Thu, 18 Feb 2010 19:46:59 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:38408 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751614Ab0BSAq5 (ORCPT ); Thu, 18 Feb 2010 19:46:57 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 19 Feb 2010 09:43:26 +0900 From: KAMEZAWA Hiroyuki To: Mel Gorman Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 09/12] Add /proc trigger for memory compaction Message-Id: <20100219094326.e725f8e8.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1266516162-14154-10-git-send-email-mel@csn.ul.ie> References: <1266516162-14154-1-git-send-email-mel@csn.ul.ie> <1266516162-14154-10-git-send-email-mel@csn.ul.ie> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 2.7.1 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5863 Lines: 196 On Thu, 18 Feb 2010 18:02:39 +0000 Mel Gorman wrote: > This patch adds a proc file /proc/sys/vm/compact_memory. When an arbitrary > value is written to the file, all zones are compacted. The expected user > of such a trigger is a job scheduler that prepares the system before the > target application runs. > > Signed-off-by: Mel Gorman > Acked-by: Rik van Riel Reviewed-by: KAMEZAWA Hiroyuki Nitpick: Hmm.. Is this necessary if we have per-node trigger in sysfs ? Thanks, -Kame > --- > Documentation/sysctl/vm.txt | 11 ++++++++ > include/linux/compaction.h | 5 +++ > kernel/sysctl.c | 11 ++++++++ > mm/compaction.c | 60 +++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 87 insertions(+), 0 deletions(-) > > diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt > index fc5790d..92b5b00 100644 > --- a/Documentation/sysctl/vm.txt > +++ b/Documentation/sysctl/vm.txt > @@ -19,6 +19,7 @@ files can be found in mm/swap.c. > Currently, these files are in /proc/sys/vm: > > - block_dump > +- compact_memory > - dirty_background_bytes > - dirty_background_ratio > - dirty_bytes > @@ -64,6 +65,16 @@ information on block I/O debugging is in Documentation/laptops/laptop-mode.txt. > > ============================================================== > > +compact_memory > + > +Available only when CONFIG_COMPACTION is set. When an arbitrary value > +is written to the file, all zones are compacted such that free memory > +is available in contiguous blocks where possible. This can be important > +for example in the allocation of huge pages although processes will also > +directly compact memory as required. > + > +============================================================== > + > dirty_background_bytes > > Contains the amount of dirty memory at which the pdflush background writeback > diff --git a/include/linux/compaction.h b/include/linux/compaction.h > index 6201371..facaa3d 100644 > --- a/include/linux/compaction.h > +++ b/include/linux/compaction.h > @@ -5,4 +5,9 @@ > #define COMPACT_INCOMPLETE 0 > #define COMPACT_COMPLETE 1 > > +#ifdef CONFIG_COMPACTION > +extern int sysctl_compaction_handler(struct ctl_table *table, int write, > + void __user *buffer, size_t *length, loff_t *ppos); > +#endif /* CONFIG_COMPACTION */ > + > #endif /* _LINUX_COMPACTION_H */ > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 8a68b24..a02c816 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -50,6 +50,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -80,6 +81,7 @@ extern int pid_max; > extern int min_free_kbytes; > extern int pid_max_min, pid_max_max; > extern int sysctl_drop_caches; > +extern int sysctl_compact_memory; > extern int percpu_pagelist_fraction; > extern int compat_log; > extern int latencytop_enabled; > @@ -1109,6 +1111,15 @@ static struct ctl_table vm_table[] = { > .mode = 0644, > .proc_handler = drop_caches_sysctl_handler, > }, > +#ifdef CONFIG_COMPACTION > + { > + .procname = "compact_memory", > + .data = &sysctl_compact_memory, > + .maxlen = sizeof(int), > + .mode = 0200, > + .proc_handler = sysctl_compaction_handler, > + }, > +#endif /* CONFIG_COMPACTION */ > { > .procname = "min_free_kbytes", > .data = &min_free_kbytes, > diff --git a/mm/compaction.c b/mm/compaction.c > index 14ba0ac..22f223f 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -11,6 +11,7 @@ > #include > #include > #include > +#include > #include "internal.h" > > /* > @@ -345,3 +346,62 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) > return ret; > } > > +/* Compact all zones within a node */ > +static int compact_node(int nid) > +{ > + int zoneid; > + pg_data_t *pgdat; > + struct zone *zone; > + > + if (nid < 0 || nid > nr_node_ids || !node_online(nid)) > + return -EINVAL; > + pgdat = NODE_DATA(nid); > + > + /* Flush pending updates to the LRU lists */ > + lru_add_drain_all(); > + > + for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) { > + struct compact_control cc; > + > + zone = &pgdat->node_zones[zoneid]; > + if (!populated_zone(zone)) > + continue; > + > + cc.nr_freepages = 0; > + cc.nr_migratepages = 0; > + cc.zone = zone; > + INIT_LIST_HEAD(&cc.freepages); > + INIT_LIST_HEAD(&cc.migratepages); > + > + compact_zone(zone, &cc); > + > + VM_BUG_ON(!list_empty(&cc.freepages)); > + VM_BUG_ON(!list_empty(&cc.migratepages)); > + } > + > + return 0; > +} > + > +/* Compact all nodes in the system */ > +static int compact_nodes(void) > +{ > + int nid; > + > + for_each_online_node(nid) > + compact_node(nid); > + > + return COMPACT_COMPLETE; > +} > + > +/* The written value is actually unused, all memory is compacted */ > +int sysctl_compact_memory; > + > +/* This is the entry point for compacting all nodes via /proc/sys/vm */ > +int sysctl_compaction_handler(struct ctl_table *table, int write, > + void __user *buffer, size_t *length, loff_t *ppos) > +{ > + if (write) > + return compact_nodes(); > + > + return 0; > +} > -- > 1.6.5 > > -- > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/