path: root/block
diff options
authorChunguang Xu <>2021-07-06 05:47:26 +0800
committerJens Axboe <>2021-07-07 06:43:20 -0600
commitd80c228d44640f0b47b57a2ca4afa26ef87e16b0 (patch)
tree1d57ac168504faa0db9558ef92eb0ce62362bdfe /block
parentc6af8db92b9a9bc89e3d25535fdc26cb61f419d0 (diff)
block: fix the problem of io_ticks becoming smaller
On the IO submission path, blk_account_io_start() may interrupt the system interruption. When the interruption returns, the value of part->stamp may have been updated by other cores, so the time value collected before the interruption may be less than part-> stamp. So when this happens, we should do nothing to make io_ticks more accurate? For kernels less than 5.0, this may cause io_ticks to become smaller, which in turn may cause abnormal ioutil values. Signed-off-by: Chunguang Xu <> Reviewed-by: Christoph Hellwig <> Link: Signed-off-by: Jens Axboe <>
Diffstat (limited to 'block')
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 3eea8d795565..04477697ee4b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1241,7 +1241,7 @@ static void update_io_ticks(struct block_device *part, unsigned long now,
unsigned long stamp;
stamp = READ_ONCE(part->bd_stamp);
- if (unlikely(stamp != now)) {
+ if (unlikely(time_after(now, stamp))) {
if (likely(cmpxchg(&part->bd_stamp, stamp, now) == stamp))
__part_stat_add(part, io_ticks, end ? now - stamp : 1);