diff options
| author | Chunguang Xu <brookxu@tencent.com> | 2021-07-06 00:47:26 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-07-07 15:43:20 +0300 |
| commit | d80c228d44640f0b47b57a2ca4afa26ef87e16b0 (patch) | |
| tree | 1d57ac168504faa0db9558ef92eb0ce62362bdfe | |
| parent | c6af8db92b9a9bc89e3d25535fdc26cb61f419d0 (diff) | |
| download | linux-d80c228d44640f0b47b57a2ca4afa26ef87e16b0.tar.xz | |
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 <brookxu@tencent.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/1625521646-1069-1-git-send-email-brookxu.cn@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-core.c | 2 |
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; again: 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); } |