Commit 194e28da authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds
Browse files

zram: add stat to gather incompressible pages since zram set up 

Currently, zram supports the stat via /sys/block/zram/mm_stat to represent
how many of incompressible pages are stored at the moment but it couldn't
show how many times incompressible pages were wrote down since zram set
up.  It's also good indication to see how zram is effective in the system.

Link: https://lkml.kernel.org/r/20201130201907.1284910-1-minchan@kernel.org


Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
Reviewed-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0d835962

Documentation/admin-guide/blockdev/zram.rst

+1 −0
Original line number Diff line number Diff line
@@ -266,6 +266,7 @@ line of text and contains the following stats separated by whitespace: 
                  No memory is allocated for such pages.

 pages_compacted  the number of pages freed during compaction

 huge_pages	  the number of incompressible pages

 huge_pages_since the number of incompressible pages since zram set up

 ================ =============================================================



File /sys/block/zram<id>/bd_stat

drivers/block/zram/zram_drv.c

+4 −2
Original line number Diff line number Diff line
@@ -1084,7 +1084,7 @@ static ssize_t mm_stat_show(struct device *dev, 
	max_used = atomic_long_read(&zram->stats.max_used_pages);



	ret = scnprintf(buf, PAGE_SIZE,

			"%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu\n",

			"%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu %8llu\n",

			orig_size << PAGE_SHIFT,

			(u64)atomic64_read(&zram->stats.compr_data_size),

			mem_used << PAGE_SHIFT,
@@ -1092,7 +1092,8 @@ static ssize_t mm_stat_show(struct device *dev, 
			max_used << PAGE_SHIFT,

			(u64)atomic64_read(&zram->stats.same_pages),

			pool_stats.pages_compacted,

			(u64)atomic64_read(&zram->stats.huge_pages));

			(u64)atomic64_read(&zram->stats.huge_pages),

			(u64)atomic64_read(&zram->stats.huge_pages_since));

	up_read(&zram->init_lock);



	return ret;
@@ -1424,6 +1425,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, 
	if (comp_len == PAGE_SIZE) {

		zram_set_flag(zram, index, ZRAM_HUGE);

		atomic64_inc(&zram->stats.huge_pages);

		atomic64_inc(&zram->stats.huge_pages_since);

	}



	if (flags) {

drivers/block/zram/zram_drv.h

+1 −0
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ struct zram_stats { 
	atomic64_t notify_free;	/* no. of swap slot free notifications */

	atomic64_t same_pages;		/* no. of same element filled pages */

	atomic64_t huge_pages;		/* no. of huge pages */

	atomic64_t huge_pages_since;	/* no. of huge pages since zram set up */

	atomic64_t pages_stored;	/* no. of pages currently stored */

	atomic_long_t max_used_pages;	/* no. of maximum pages stored */

	atomic64_t writestall;		/* no. of write slow paths */