Messages in this thread | | | Date | Sat, 9 May 2015 13:21:48 +0900 | From | Sergey Senozhatsky <> | Subject | what's cooking in zram for 4.1 |
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Hello Karel,
There will be some user-space visible changes in zram 4.1 we'd love to let you know about.
1) new sysfs node -- /sys/block/zramX/compact
triggers zram memory compaction.
2) zram has deprecated some of the existing stat sysfs attributes. we will consolidate zramX device's stats in 3 files, rather than having N files (per-stat).
The idea is: -- the existing RW sysfs device nodes will be downgraded to WO nodes (in linux 4.11) -- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
User-space is advised to use the following files:
-- /sys/block/zram<id>/stat
Represents block layer statistics (read Documentation/block/stat.txt for details).
-- /sys/block/zram<id>/io_stat
The stat file represents device's I/O statistics not accounted by block layer and, thus, not available in zram<id>/stat file. It consists of a single line of text and contains the following stats separated by whitespace: failed_reads failed_writes invalid_io notify_free
-- /sys/block/zram<id>/mm_stat
The stat file represents device's mm statistics. It consists of a single line of text and contains the following stats separated by whitespace: orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated
deprecated nodes will be around up until linux 4.11 (approx 2 years from now). in the meantime, zram will warn (once) should any user space app access any of the deprecated attrs: "zram: 30788 (cat) Attribute num_reads (and others) will be removed. See zram documentation."
-ss
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