kevin/linux
1
Fork 0
Code

zram: add incompressible flag to read_block_state()

Browse Source 
Add a new flag to zram block state that shows if the page is
incompressible: that none of the algorithm (including secondary ones)
could compress it.

Link: https://lkml.kernel.org/r/20221109115047.2921851-14-senozhatsky@chromium.org
Suggested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Sergey Senozhatsky 2022-11-09 20:50:47 +09:00 committed by Andrew Morton
parent b46f9ea3cb
commit 77db7bb56b
2 changed files with 11 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
Documentation/admin-guide/blockdev/zram.rst
View File

@ -497,10 +497,11 @@ pages of the process with*pagemap.
If you enable the feature, you could see block state via
/sys/kernel/debug/zram/zram0/block_state". The output is as follows::
300 75.033841 .wh..
301 63.806904 s....
302 63.806919 ..hi.
303 62.801919 ....r
300 75.033841 .wh...
301 63.806904 s.....
302 63.806919 ..hi..
303 62.801919 ....r.
304 146.781902 ..hi.n
First column
zram's block index.
@ -519,6 +520,8 @@ Third column
idle page
r:
recompressed page (secondary compression algorithm)
n:
none (including secondary) of algorithms could compress it
First line of above example says 300th block is accessed at 75.033841sec
and the block's state is huge so it is written back to the backing

6
drivers/block/zram/zram_drv.c
View File

@ -946,14 +946,16 @@ static ssize_t read_block_state(struct file *file, char __user *buf,
ts = ktime_to_timespec64(zram->table[index].ac_time);
copied = snprintf(kbuf + written, count,
"%12zd %12lld.%06lu %c%c%c%c%c\n",
"%12zd %12lld.%06lu %c%c%c%c%c%c\n",
index, (s64)ts.tv_sec,
ts.tv_nsec / NSEC_PER_USEC,
zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.',
zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.',
zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.',
zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.',
zram_get_priority(zram, index) ? 'r' : '.');
zram_get_priority(zram, index) ? 'r' : '.',
zram_test_flag(zram, index,
ZRAM_INCOMPRESSIBLE) ? 'n' : '.');
if (count <= copied) {
zram_slot_unlock(zram, index);