Re: [PATCH] blk-cgroup: Fix the recursive blkg rwstat

From: Tejun Heo
Date: Sun Mar 07 2021 - 07:43:23 EST


On Fri, Mar 05, 2021 at 11:32:05AM -0700, Jens Axboe wrote:
> On 3/5/21 1:13 AM, Xunlei Pang wrote:
> > The current blkio.throttle.io_service_bytes_recursive doesn't
> > work correctly.
> >
> > As an example, for the following blkcg hierarchy:
> > (Made 1GB READ in test1, 512MB READ in test2)
> > test
> > / \
> > test1 test2
> >
> > $ head -n 1 test/test1/blkio.throttle.io_service_bytes_recursive
> > 8:0 Read 1073684480
> > $ head -n 1 test/test2/blkio.throttle.io_service_bytes_recursive
> > 8:0 Read 537448448
> > $ head -n 1 test/blkio.throttle.io_service_bytes_recursive
> > 8:0 Read 537448448
> >
> > Clearly, above data of "test" reflects "test2" not "test1"+"test2".
> >
> > Do the correct summary in blkg_rwstat_recursive_sum().
>
> LGTM, Tejun?

Gees, that's horrible. Thanks for fixing this.

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

--
tejun