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authorGanesh Mahendran <opensource.ganesh@gmail.com>2015-02-12 15:00:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 18:54:12 -0800
commit0f050d997e275cf0e47ddc7006284eaa3c6fe049 (patch)
tree380ee8b8b699a07a6b52c545310a8b4f65f8f6d6 /mm/Kconfig
parent3eba0c6a56c04f2b017b43641a821f1ebfb7fb4c (diff)
downloadlinux-0f050d997e275cf0e47ddc7006284eaa3c6fe049.tar.bz2
mm/zsmalloc: add statistics support
Keeping fragmentation of zsmalloc in a low level is our target. But now we still need to add the debug code in zsmalloc to get the quantitative data. This patch adds a new configuration CONFIG_ZSMALLOC_STAT to enable the statistics collection for developers. Currently only the objects statatitics in each class are collected. User can get the information via debugfs. cat /sys/kernel/debug/zsmalloc/zram0/... For example: After I copied "jdk-8u25-linux-x64.tar.gz" to zram with ext4 filesystem: class size obj_allocated obj_used pages_used 0 32 0 0 0 1 48 256 12 3 2 64 64 14 1 3 80 51 7 1 4 96 128 5 3 5 112 73 5 2 6 128 32 4 1 7 144 0 0 0 8 160 0 0 0 9 176 0 0 0 10 192 0 0 0 11 208 0 0 0 12 224 0 0 0 13 240 0 0 0 14 256 16 1 1 15 272 15 9 1 16 288 0 0 0 17 304 0 0 0 18 320 0 0 0 19 336 0 0 0 20 352 0 0 0 21 368 0 0 0 22 384 0 0 0 23 400 0 0 0 24 416 0 0 0 25 432 0 0 0 26 448 0 0 0 27 464 0 0 0 28 480 0 0 0 29 496 33 1 4 30 512 0 0 0 31 528 0 0 0 32 544 0 0 0 33 560 0 0 0 34 576 0 0 0 35 592 0 0 0 36 608 0 0 0 37 624 0 0 0 38 640 0 0 0 40 672 0 0 0 42 704 0 0 0 43 720 17 1 3 44 736 0 0 0 46 768 0 0 0 49 816 0 0 0 51 848 0 0 0 52 864 14 1 3 54 896 0 0 0 57 944 13 1 3 58 960 0 0 0 62 1024 4 1 1 66 1088 15 2 4 67 1104 0 0 0 71 1168 0 0 0 74 1216 0 0 0 76 1248 0 0 0 83 1360 3 1 1 91 1488 11 1 4 94 1536 0 0 0 100 1632 5 1 2 107 1744 0 0 0 111 1808 9 1 4 126 2048 4 4 2 144 2336 7 3 4 151 2448 0 0 0 168 2720 15 15 10 190 3072 28 27 21 202 3264 0 0 0 254 4096 36209 36209 36209 Total 37022 36326 36288 We can calculate the overall fragentation by the last line: Total 37022 36326 36288 (37022 - 36326) / 37022 = 1.87% Also by analysing objects alocated in every class we know why we got so low fragmentation: Most of the allocated objects is in <class 254>. And there is only 1 page in class 254 zspage. So, No fragmentation will be introduced by allocating objs in class 254. And in future, we can collect other zsmalloc statistics as we need and analyse them. Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/Kconfig')
-rw-r--r--mm/Kconfig10
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 4395b12869c8..de5239c152f9 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -602,6 +602,16 @@ config PGTABLE_MAPPING
You can check speed with zsmalloc benchmark:
https://github.com/spartacus06/zsmapbench
+config ZSMALLOC_STAT
+ bool "Export zsmalloc statistics"
+ depends on ZSMALLOC
+ select DEBUG_FS
+ help
+ This option enables code in the zsmalloc to collect various
+ statistics about whats happening in zsmalloc and exports that
+ information to userspace via debugfs.
+ If unsure, say N.
+
config GENERIC_EARLY_IOREMAP
bool