diff options
author | Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> | 2018-04-05 16:24:47 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:26 -0700 |
commit | 60f5921a9a4f126e081318bd6bb2bc2798b7bba8 (patch) | |
tree | 46121f0c217ab40a3da0b439ca0899a9372fce73 | |
parent | 010b495e2fa32353d0ef6aa70a8169e5ef617a15 (diff) |
zram: drop max_zpage_size and use zs_huge_class_size()
Remove ZRAM's enforced "huge object" value and use zsmalloc huge-class
watermark instead, which makes more sense.
TEST
- I used a 1G zram device, LZO compression back-end, original
data set size was 444MB. Looking at zsmalloc classes stats the
test ended up to be pretty fair.
BASE ZRAM/ZSMALLOC
=====================
zram mm_stat
498978816 191482495 199831552 0 199831552 15634 0
zsmalloc classes
class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable
...
151 2448 0 0 1240 1240 744 3 0
168 2720 0 0 4200 4200 2800 2 0
190 3072 0 0 10100 10100 7575 3 0
202 3264 0 0 380 380 304 4 0
254 4096 0 0 10620 10620 10620 1 0
Total 7 46 106982 106187 48787 0
PATCHED ZRAM/ZSMALLOC
=====================
zram mm_stat
498978816 182579184 194248704 0 194248704 15628 0
zsmalloc classes
class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable
...
151 2448 0 0 1240 1240 744 3 0
168 2720 0 0 4200 4200 2800 2 0
190 3072 0 0 10100 10100 7575 3 0
202 3264 0 0 7180 7180 5744 4 0
254 4096 0 0 3820 3820 3820 1 0
Total 8 45 106959 106193 47424 0
As we can see, we reduced the number of objects stored in class-4096,
because a huge number of objects which we previously forcibly stored in
class-4096 now stored in non-huge class-3264. This results in lower
memory consumption:
- zsmalloc now uses 47424 physical pages, which is less than 48787 pages
zsmalloc used before.
- objects that we store in class-3264 share zspages. That's why overall
the number of pages that both class-4096 and class-3264 consumed went
down from 10924 to 9564.
[sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()]
Link: http://lkml.kernel.org/r/20180314081833.1096-3-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20180306070639.7389-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | drivers/block/zram/zram_drv.c | 9 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.h | 16 |
2 files changed, 8 insertions, 17 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 0afa6c8c3857..bd38f46801d3 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -44,6 +44,11 @@ static const char *default_compressor = "lzo"; /* Module params (documentation at end) */ static unsigned int num_devices = 1; +/* + * Pages that compress to sizes equals or greater than this are stored + * uncompressed in memory. + */ +static size_t huge_class_size; static void zram_free_page(struct zram *zram, size_t index); @@ -786,6 +791,8 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) return false; } + if (!huge_class_size) + huge_class_size = zs_huge_class_size(zram->mem_pool); return true; } @@ -965,7 +972,7 @@ compress_again: return ret; } - if (unlikely(comp_len > max_zpage_size)) { + if (unlikely(comp_len >= huge_class_size)) { if (zram_wb_enabled(zram) && allow_wb) { zcomp_stream_put(zram->comp); ret = write_to_bdev(zram, bvec, index, bio, &element); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 31762db861e3..d71c8000a964 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -21,22 +21,6 @@ #include "zcomp.h" -/*-- Configurable parameters */ - -/* - * Pages that compress to size greater than this are stored - * uncompressed in memory. - */ -static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; - -/* - * NOTE: max_zpage_size must be less than or equal to: - * ZS_MAX_ALLOC_SIZE. Otherwise, zs_malloc() would - * always return failure. - */ - -/*-- End of configurable params */ - #define SECTOR_SHIFT 9 #define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) #define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) |