Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751855Ab0DMMmw (ORCPT ); Tue, 13 Apr 2010 08:42:52 -0400 Received: from gir.skynet.ie ([193.1.99.77]:49048 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751694Ab0DMMmv (ORCPT ); Tue, 13 Apr 2010 08:42:51 -0400 Date: Tue, 13 Apr 2010 13:42:26 +0100 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 , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 05/14] Export unusable free space index via /proc/unusable_index Message-ID: <20100413124226.GV25756@csn.ul.ie> References: <1270224168-14775-1-git-send-email-mel@csn.ul.ie> <1270224168-14775-6-git-send-email-mel@csn.ul.ie> <20100406170537.c84f54b7.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100406170537.c84f54b7.akpm@linux-foundation.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8612 Lines: 285 On Tue, Apr 06, 2010 at 05:05:37PM -0700, Andrew Morton wrote: > > > All this code will be bloat for most people, I suspect. Can we find a > suitable #ifdef wrapper to keep my cellphone happy? > ==== CUT HERE ==== mm,compaction: Move unusable_index to debugfs unusable_index can be worked out from userspace but for debugging and tuning compaction, it'd be best for all users to have the same information. This patch moves extfrag_index to debugfs where it is both easier to configure out and remove at some future date. This is a fix to the patch "Export unusable free space index via /proc/unusable_index" Signed-off-by: Mel Gorman --- Documentation/filesystems/proc.txt | 13 +--- mm/vmstat.c | 183 ++++++++++++++++++++---------------- 2 files changed, 105 insertions(+), 91 deletions(-) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index e87775a..74d2605 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -453,7 +453,6 @@ Table 1-5: Kernel info in /proc sys See chapter 2 sysvipc Info of SysVIPC Resources (msg, sem, shm) (2.4) tty Info of tty drivers - unusable_index Additional page allocator information (see text)(2.5) uptime System uptime version Kernel version video bttv info of video resources (2.4) @@ -611,7 +610,7 @@ ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE available in ZONE_NORMAL, etc... More information relevant to external fragmentation can be found in -pagetypeinfo and unusable_index +pagetypeinfo. > cat /proc/pagetypeinfo Page block order: 9 @@ -652,16 +651,6 @@ unless memory has been mlock()'d. Some of the Reclaimable blocks should also be allocatable although a lot of filesystem metadata may have to be reclaimed to achieve this. -> cat /proc/unusable_index -Node 0, zone DMA 0.000 0.000 0.000 0.001 0.005 0.013 0.021 0.037 0.037 0.101 0.230 -Node 0, zone Normal 0.000 0.000 0.000 0.001 0.002 0.002 0.005 0.015 0.028 0.028 0.054 - -The unusable free space index measures how much of the available free -memory cannot be used to satisfy an allocation of a given size and is a -value between 0 and 1. The higher the value, the more of free memory is -unusable and by implication, the worse the external fragmentation is. This -can be expressed as a percentage by multiplying by 100. - .............................................................................. meminfo: diff --git a/mm/vmstat.c b/mm/vmstat.c index 2fb4986..0dcf08d 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -453,7 +453,6 @@ static int frag_show(struct seq_file *m, void *arg) return 0; } - struct contig_page_info { unsigned long free_pages; unsigned long free_blocks_total; @@ -495,64 +494,6 @@ static void fill_contig_page_info(struct zone *zone, } } -/* - * Return an index indicating how much of the available free memory is - * unusable for an allocation of the requested size. - */ -static int unusable_free_index(unsigned int order, - struct contig_page_info *info) -{ - /* No free memory is interpreted as all free memory is unusable */ - if (info->free_pages == 0) - return 1000; - - /* - * Index should be a value between 0 and 1. Return a value to 3 - * decimal places. - * - * 0 => no fragmentation - * 1 => high fragmentation - */ - return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); - -} - -static void unusable_show_print(struct seq_file *m, - pg_data_t *pgdat, struct zone *zone) -{ - unsigned int order; - int index; - struct contig_page_info info; - - seq_printf(m, "Node %d, zone %8s ", - pgdat->node_id, - zone->name); - for (order = 0; order < MAX_ORDER; ++order) { - fill_contig_page_info(zone, order, &info); - index = unusable_free_index(order, &info); - seq_printf(m, "%d.%03d ", index / 1000, index % 1000); - } - - seq_putc(m, '\n'); -} - -/* - * Display unusable free space index - * XXX: Could be a lot more efficient, but it's not a critical path - */ -static int unusable_show(struct seq_file *m, void *arg) -{ - pg_data_t *pgdat = (pg_data_t *)arg; - - /* check memoryless node */ - if (!node_state(pgdat->node_id, N_HIGH_MEMORY)) - return 0; - - walk_zones_in_node(m, pgdat, unusable_show_print); - - return 0; -} - static void pagetypeinfo_showfree_print(struct seq_file *m, pg_data_t *pgdat, struct zone *zone) { @@ -703,25 +644,6 @@ static const struct file_operations pagetypeinfo_file_ops = { .release = seq_release, }; -static const struct seq_operations unusable_op = { - .start = frag_start, - .next = frag_next, - .stop = frag_stop, - .show = unusable_show, -}; - -static int unusable_open(struct inode *inode, struct file *file) -{ - return seq_open(file, &unusable_op); -} - -static const struct file_operations unusable_file_ops = { - .open = unusable_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - #ifdef CONFIG_ZONE_DMA #define TEXT_FOR_DMA(xx) xx "_dma", #else @@ -1066,10 +988,113 @@ static int __init setup_vmstat(void) #ifdef CONFIG_PROC_FS proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations); proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops); - proc_create("unusable_index", S_IRUGO, NULL, &unusable_file_ops); proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations); proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations); #endif return 0; } module_init(setup_vmstat) + +#ifdef CONFIG_DEBUG_FS +#include +#include + +static struct dentry *extfrag_debug_root; + +/* + * Return an index indicating how much of the available free memory is + * unusable for an allocation of the requested size. + */ +static int unusable_free_index(unsigned int order, + struct contig_page_info *info) +{ + /* No free memory is interpreted as all free memory is unusable */ + if (info->free_pages == 0) + return 1000; + + /* + * Index should be a value between 0 and 1. Return a value to 3 + * decimal places. + * + * 0 => no fragmentation + * 1 => high fragmentation + */ + return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); + +} + +static void unusable_show_print(struct seq_file *m, + pg_data_t *pgdat, struct zone *zone) +{ + unsigned int order; + int index; + struct contig_page_info info; + + seq_printf(m, "Node %d, zone %8s ", + pgdat->node_id, + zone->name); + for (order = 0; order < MAX_ORDER; ++order) { + fill_contig_page_info(zone, order, &info); + index = unusable_free_index(order, &info); + seq_printf(m, "%d.%03d ", index / 1000, index % 1000); + } + + seq_putc(m, '\n'); +} + +/* + * Display unusable free space index + * + * The unusable free space index measures how much of the available free + * memory cannot be used to satisfy an allocation of a given size and is a + * value between 0 and 1. The higher the value, the more of free memory is + * unusable and by implication, the worse the external fragmentation is. This + * can be expressed as a percentage by multiplying by 100. + */ +static int unusable_show(struct seq_file *m, void *arg) +{ + pg_data_t *pgdat = (pg_data_t *)arg; + + /* check memoryless node */ + if (!node_state(pgdat->node_id, N_HIGH_MEMORY)) + return 0; + + walk_zones_in_node(m, pgdat, unusable_show_print); + + return 0; +} + +static const struct seq_operations unusable_op = { + .start = frag_start, + .next = frag_next, + .stop = frag_stop, + .show = unusable_show, +}; + +static int unusable_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &unusable_op); +} + +static const struct file_operations unusable_file_ops = { + .open = unusable_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init extfrag_debug_init(void) +{ + extfrag_debug_root = debugfs_create_dir("extfrag", NULL); + if (!extfrag_debug_root) + return -ENOMEM; + + if (!debugfs_create_file("unusable_index", 0444, + extfrag_debug_root, NULL, &unusable_file_ops)) + return -ENOMEM; + + return 0; +} + +module_init(extfrag_debug_init); +#endif -- 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/