Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755455Ab0DTVCb (ORCPT ); Tue, 20 Apr 2010 17:02:31 -0400 Received: from gir.skynet.ie ([193.1.99.77]:47024 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755348Ab0DTVBR (ORCPT ); Tue, 20 Apr 2010 17:01:17 -0400 From: Mel Gorman To: Andrew Morton Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Minchan Kim , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 10/14] mm,compaction: Add /proc trigger for memory compaction Date: Tue, 20 Apr 2010 22:01:12 +0100 Message-Id: <1271797276-31358-11-git-send-email-mel@csn.ul.ie> X-Mailer: git-send-email 1.6.5 In-Reply-To: <1271797276-31358-1-git-send-email-mel@csn.ul.ie> References: <1271797276-31358-1-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5075 Lines: 173 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 Reviewed-by: Minchan Kim Reviewed-by: KOSAKI Motohiro Reviewed-by: Christoph Lameter --- Documentation/sysctl/vm.txt | 10 +++++++ include/linux/compaction.h | 6 ++++ kernel/sysctl.c | 10 +++++++ mm/compaction.c | 61 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 87 insertions(+), 0 deletions(-) diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 56366a5..3b3fa1b 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 +65,15 @@ information on block I/O debugging is in Documentation/laptops/laptop-mode.txt. ============================================================== +compact_memory + +Available only when CONFIG_COMPACTION is set. When 1 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 465ca88..5723888 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -6,4 +6,10 @@ #define COMPACT_PARTIAL 1 #define COMPACT_COMPLETE 2 +#ifdef CONFIG_COMPACTION +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); +#endif /* CONFIG_COMPACTION */ + #endif /* _LINUX_COMPACTION_H */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 26f25eb..987d6cf 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -1121,6 +1122,15 @@ 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 1b80dd8..5e4444c 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "internal.h" /* @@ -392,3 +393,63 @@ 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 = { + .nr_freepages = 0, + .nr_migratepages = 0, + }; + + zone = &pgdat->node_zones[zoneid]; + if (!populated_zone(zone)) + continue; + + 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 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/