On 7/5/21 3:47 PM, brookxu wrote:

From: Chunguang Xu <redacted>

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.

v3: update the commit log
v2: sorry, fix compile error due to the missed ')'

The version log goes below the '---' in the email, not in the commit
message. I fixed that up. Applied for 5.14, thanks.

-- 
Jens Axboe