zram: add recompress flag to read_block_state()

Add a new flag to zram block state that shows if the page was recompressed
(using alternative compression algorithm).

Link: https://lkml.kernel.org/r/20221109115047.2921851-6-senozhatsky@chromium.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>

diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst
index c73b16930449e6eb1efe62aa8ab774c113db6343..177a142c3146dc32592f32b4db7ba6362eb9c95d 100644 (file)
--- a/Documentation/admin-guide/blockdev/zram.rst
+++ b/Documentation/admin-guide/blockdev/zram.rst
@@ -411,9 +411,10 @@ 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
+         300    75.033841 .wh..
+         301    63.806904 s....
+         302    63.806919 ..hi.
+         303    62.801919 ....r
 
 First column
        zram's block index.
@@ -430,6 +431,8 @@ Third column
                huge page
        i:
                idle page
+       r:
+               recompressed page (secondary compression algorithm)
 
 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 97300b3a83c30f3e355c6339a77b8c36e837dc6f..ddbfa70ef9a331b9e05e2ce4955cf3c4bbc22ee3 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -936,13 +936,14 @@ 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\n",
+                       "%12zd %12lld.%06lu %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_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.',
+                       zram_get_priority(zram, index) ? 'r' : '.');
 
                if (count <= copied) {
                        zram_slot_unlock(zram, index);