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(+) diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index 70ec992..fa8936e 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -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]> diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 0595c3f..e50e18b 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -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 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index d00831c..904e7a5 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -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, diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index e0f725c..2994aaf 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -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 */ -- 2.0.1.474.g72c7794 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
