Re: [PATCHSET v3 block/for-next] blkcg: Improve blkg config helpers and make iolatency init lazy

[Yu Kuai]

Hi,

在 2023/01/11 6:27, Tejun Heo 写道:
> Hello,
>
> * v2[2] fixes the build failure caused by v1[1] forgetting to update bfq.
>
> * v3 drops __acuquires/__releases() changes and updates patch descriptions.
>
> This patchset:
>
> * Improves blkg config helpers so that they can be used consistently for all
>    the existing use cases. This also allows keeps using the same bdev open
>    instance across lazy init of rq_qos policies.
>
> * Updates iolatency so that it initializes lazily when a latency target is
>    set for the first time. This avoids registering the rq_qos policy when
>    iolatency is not used which removes unnecessary calls into iolat from IO
>    hot paths.

There are some rq_qos and iocost bugfix based on this patchset, can
anyone help to review this patchset?

Thanks,
Kuai

> and contains the following four patches:
>
>   0001-blkcg-Drop-unnecessary-RCU-read-un-locks-from-blkg_c.patch
>   0002-blkcg-Restructure-blkg_conf_prep-and-friends.patch
>   0003-blk-iolatency-s-blkcg_rq_qos-iolat_rq_qos.patch
>   0004-blk-iolatency-Make-initialization-lazy.patch
>
> and is also available in the following git branch.
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git iolat-lazy-init-v2
>
> diffstat follows. Thanks.
>
>   block/bfq-cgroup.c    |    8 ++-
>   block/blk-cgroup.c    |  122 ++++++++++++++++++++++++++++----------------------
>   block/blk-cgroup.h    |   10 ++--
>   block/blk-iocost.c    |   58 +++++++++++++----------
>   block/blk-iolatency.c |   39 +++++++++++++--
>   block/blk-rq-qos.h    |    2
>   block/blk-throttle.c  |   16 ++++--
>   block/blk.h           |    6 --
>   8 files changed, 159 insertions(+), 102 deletions(-)
>
> [1] https://lkml.kernel.org/r/20230105002007.157497-1-tj@xxxxxxxxxx
> [2] https://lkml.kernel.org/r/20230105212432.289569-1-tj@xxxxxxxxxx
>
> --
> tejun
>
> .