zram: add num_discards for discarded pages stat
Subsystems (4)
PATCH v2 1/1 zram: add num_discards for discarded pages stat
Now we have supported handling discard request which is sended by filesystem, but no interface could be used to show information of discard. This patch adds num_discards to stat discarded pages, then export it to sysfs for displaying.
v2: update zram document.
Signed-off-by Chao Yu <[email protected]>
--- Documentation/ABI/testing/sysfs-block-zram | 10 ++++++++++ Documentation/blockdev/zram.txt | 1 + drivers/block/zram/zram_drv.c | 3 +++ drivers/block/zram/zram_drv.h | 1 + 4 files changed, 15 insertions(+)
Documentation/ABI/testing/sysfs-block-zram +10 -0
@@ -57,6 +57,16 @@ Description: The failed_writes file is read-only and specifies the number of failed writes happened on this device. + +What: /sys/block/zram<id>/num_discards +Date: August 2014 +Contact: Chao Yu <[email protected]> +Description: + The num_discards file is read-only and specifies the number of + physical blocks which are discarded by this device. These blocks + are included in discard request which is sended by filesystem as + the blocks are no longer used. + What: /sys/block/zram<id>/max_comp_streams Date: February 2014 Contact: Sergey Senozhatsky <[email protected]>
Documentation/blockdev/zram.txt +1 -0
@@ -89,6 +89,7 @@ size of the disk when not in use so a huge zram is wasteful. num_writes failed_reads failed_writes + num_discards invalid_io notify_free zero_pages
drivers/block/zram/zram_drv.c +3 -0
@@ -606,6 +606,7 @@ static void zram_bio_discard(struct zram *zram, u32 index,bit_spin_lock (ZRAM_ACCESS , &meta->table[index].value);zram_free_page (zram, index);bit_spin_unlock (ZRAM_ACCESS , &meta->table[index].value); +atomic64_inc (&zram->stats.num_discards); index++; n -=PAGE_SIZE ; }
@@ -866,6 +867,7 @@ ZRAM_ATTR_RO(num_reads);ZRAM_ATTR_RO (num_writes);ZRAM_ATTR_RO (failed_reads);ZRAM_ATTR_RO (failed_writes); +ZRAM_ATTR_RO (num_discards);ZRAM_ATTR_RO (invalid_io);ZRAM_ATTR_RO (notify_free);ZRAM_ATTR_RO (zero_pages);
@@ -879,6 +881,7 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_num_writes.attr, &dev_attr_failed_reads.attr, &dev_attr_failed_writes.attr, + &dev_attr_num_discards.attr, &dev_attr_invalid_io.attr, &dev_attr_notify_free.attr, &dev_attr_zero_pages.attr,
drivers/block/zram/zram_drv.h +1 -0
@@ -86,6 +86,7 @@ struct zram_stats {atomic64_t num_writes;/* --do-- */ atomic64_t failed_reads;/* can happen when memory is too low */ atomic64_t failed_writes;/* can happen when memory is too low */ +atomic64_t num_discards;/* no. of discarded pages */ atomic64_t invalid_io;/* non-page-aligned I/O requests */ atomic64_t notify_free;/* no. of swap slot free notifications */ atomic64_t zero_pages;/* no. of zero filled pages */
Signature · 1 line
2.0.1.474.g72c7794