From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com [209.85.220.46]) by kanga.kvack.org (Postfix) with ESMTP id D01D96B0256 for ; Mon, 29 Feb 2016 11:15:26 -0500 (EST) Received: by mail-pa0-f46.google.com with SMTP id fy10so94205682pac.1 for ; Mon, 29 Feb 2016 08:15:26 -0800 (PST) Received: from mail-pf0-x22d.google.com (mail-pf0-x22d.google.com. [2607:f8b0:400e:c00::22d]) by mx.google.com with ESMTPS id fn9si43891519pab.163.2016.02.29.08.15.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Feb 2016 08:15:25 -0800 (PST) Received: by mail-pf0-x22d.google.com with SMTP id 124so33025883pfg.0 for ; Mon, 29 Feb 2016 08:15:25 -0800 (PST) From: Sergey Senozhatsky Subject: [PATCHv2] mm/zsmalloc: add `freeable' column to pool stat Date: Tue, 1 Mar 2016 01:13:19 +0900 Message-Id: <1456762399-25744-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Add a new column to pool stats, which will tell how many pages ideally can be freed by class compaction, so it will be easier to analyze zsmalloc fragmentation. At the moment, we have only numbers of FULL and ALMOST_EMPTY classes, but they don't tell us how badly the class is fragmented internally. The new /sys/kernel/debug/zsmalloc/zramX/classes output look as follows: class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable [..] 12 224 0 2 146 5 8 4 4 13 240 0 0 0 0 0 1 0 14 256 1 13 1840 1672 115 1 10 15 272 0 0 0 0 0 1 0 [..] 49 816 0 3 745 735 149 1 2 51 848 3 4 361 306 76 4 8 52 864 12 14 378 268 81 3 21 54 896 1 12 117 57 26 2 12 57 944 0 0 0 0 0 3 0 [..] Total 26 131 12709 10994 1071 134 For example, from this particular output we can easily conclude that class-896 is heavily fragmented -- it occupies 26 pages, 12 can be freed by compaction. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- v2: -- rename column to `freeable' (Minchan) mm/zsmalloc.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 824fb3f..1023e0d 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -503,6 +503,8 @@ static void __exit zs_stat_exit(void) debugfs_remove_recursive(zs_stat_root); } +static unsigned long zs_can_compact(struct size_class *class); + static int zs_stats_size_show(struct seq_file *s, void *v) { int i; @@ -510,14 +512,15 @@ static int zs_stats_size_show(struct seq_file *s, void *v) struct size_class *class; int objs_per_zspage; unsigned long class_almost_full, class_almost_empty; - unsigned long obj_allocated, obj_used, pages_used; + unsigned long obj_allocated, obj_used, pages_used, freeable; unsigned long total_class_almost_full = 0, total_class_almost_empty = 0; unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; + unsigned long total_freeable = 0; - seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s\n", + seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n", "class", "size", "almost_full", "almost_empty", "obj_allocated", "obj_used", "pages_used", - "pages_per_zspage"); + "pages_per_zspage", "freeable"); for (i = 0; i < zs_size_classes; i++) { class = pool->size_class[i]; @@ -530,6 +533,7 @@ static int zs_stats_size_show(struct seq_file *s, void *v) class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY); obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); obj_used = zs_stat_get(class, OBJ_USED); + freeable = zs_can_compact(class); spin_unlock(&class->lock); objs_per_zspage = get_maxobj_per_zspage(class->size, @@ -537,23 +541,25 @@ static int zs_stats_size_show(struct seq_file *s, void *v) pages_used = obj_allocated / objs_per_zspage * class->pages_per_zspage; - seq_printf(s, " %5u %5u %11lu %12lu %13lu %10lu %10lu %16d\n", + seq_printf(s, " %5u %5u %11lu %12lu %13lu" + " %10lu %10lu %16d %8lu\n", i, class->size, class_almost_full, class_almost_empty, obj_allocated, obj_used, pages_used, - class->pages_per_zspage); + class->pages_per_zspage, freeable); total_class_almost_full += class_almost_full; total_class_almost_empty += class_almost_empty; total_objs += obj_allocated; total_used_objs += obj_used; total_pages += pages_used; + total_freeable += freeable; } seq_puts(s, "\n"); - seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu\n", + seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %7lu\n", "Total", "", total_class_almost_full, total_class_almost_empty, total_objs, - total_used_objs, total_pages); + total_used_objs, total_pages, "", total_freeable); return 0; } -- 2.8.0.rc0 -- 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