diff options
| author | Minchan Kim <minchan@kernel.org> | 2014-10-09 15:29:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 22:26:02 -0400 |
| commit | 9ada9da9573f3460b156b7755c093e30b258eacb (patch) | |
| tree | 45d38673aa9bc81b99131a3a3c5e1e97292bb5f5 /Documentation | |
| parent | 722cdc17232f0f684011407f7cf3c40d39457971 (diff) | |
zram: zram memory size limitation
Since zram has no control feature to limit memory usage, it makes hard to
manage system memrory.
This patch adds new knob "mem_limit" via sysfs to set up the a limit so
that zram could fail allocation once it reaches the limit.
In addition, user could change the limit in runtime so that he could
manage the memory more dynamically.
Initial state is no limit so it doesn't break old behavior.
[akpm@linux-foundation.org: fix typo, per Sergey]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: <juno.choi@lge.com>
Cc: <seungho1.park@lge.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: David Horner <ds2horner@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-zram | 9 | ||||
| -rw-r--r-- | Documentation/blockdev/zram.txt | 24 |
2 files changed, 29 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index 70ec992514d..ea67fa3f3cf 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -119,3 +119,12 @@ Description: efficiency can be calculated using compr_data_size and this statistic. Unit: bytes + +What: /sys/block/zram<id>/mem_limit +Date: August 2014 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The mem_limit file is read/write and specifies the maximum + amount of memory ZRAM can use to store the compressed data. The + limit could be changed in run time and "0" means disable the + limit. No limit is the initial state. Unit: bytes diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 0595c3f56cc..82c6a41116d 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -74,14 +74,30 @@ There is little point creating a zram of greater than twice the size of memory since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the size of the disk when not in use so a huge zram is wasteful. -5) Activate: +5) Set memory limit: Optional + Set memory limit by writing the value to sysfs node 'mem_limit'. + The value can be either in bytes or you can use mem suffixes. + In addition, you could change the value in runtime. + Examples: + # limit /dev/zram0 with 50MB memory + echo $((50*1024*1024)) > /sys/block/zram0/mem_limit + + # Using mem suffixes + echo 256K > /sys/block/zram0/mem_limit + echo 512M > /sys/block/zram0/mem_limit + echo 1G > /sys/block/zram0/mem_limit + + # To disable memory limit + echo 0 > /sys/block/zram0/mem_limit + +6) Activate: mkswap /dev/zram0 swapon /dev/zram0 mkfs.ext4 /dev/zram1 mount /dev/zram1 /tmp -6) Stats: +7) Stats: Per-device statistics are exported as various nodes under /sys/block/zram<id>/ disksize @@ -96,11 +112,11 @@ size of the disk when not in use so a huge zram is wasteful. compr_data_size mem_used_total -7) Deactivate: +8) Deactivate: swapoff /dev/zram0 umount /dev/zram1 -8) Reset: +9) Reset: Write any positive value to 'reset' sysfs node echo 1 > /sys/block/zram0/reset echo 1 > /sys/block/zram1/reset |