Re: [PATCH V3 2/8] md: add io accounting for raid0 and raid5

Hi Song,

On 5/27/21 2:14 PM, Song Liu wrote:

quoted

Could you point the place where md enables iostats before the set?
I can't find relevant code for it.

Before this set, we did not set QUEUE_FLAG_IO_STAT, and we didn't
check blk_queue_io_stat() either. So even with /sys/block/mdX/queue/iostats
of 0, we still get iostats for the md device. By setting QUEUE_FLAG_IO_STAT
with the patch, the users still get iostats working by default.

I am okay with enable it by default,  though users need to know the
parameter given it affects the performance.

Thanks,
Guoqing