From: Sergey Senozhatsky senozhatsky@chromium.org
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 Signed-off-by: Jinjiang Tu tujinjiang@huawei.com --- Documentation/admin-guide/blockdev/zram.rst | 11 +++++++---- drivers/block/zram/zram_drv.c | 6 ++++-- 2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index bce2e4480652..3bfb9dc67976 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -478,10 +478,11 @@ 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. @@ -500,6 +501,8 @@ 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 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 1e56e5ff562d..7e706e3eab8d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -929,14 +929,16 @@ 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);