Hi Jens, On Tue, Sep 11, 2018 at 02:41:25PM -0400, Dennis Zhou wrote: > Hi everyone, > > v3: a few minor fixes. > 0003: Updated the comment to bio_associate_blkg to reflect closest > association. > Removed a return branch in __bio_lookup_create. > 0009: Removed an unnecessary rcu_read_(un)lock pair. > 0010: Fixed blkg null pointer... blkg->blkcg => blkcg. > > This is rebased onto axboe#for-4.20/block 902d53914f64. > > From v2 below (updated): > ------ > This is a followup to the patch series I sent out earlier [1] containing > the middle two points: > 1. always associate a bio with a blkg > 2. remove the extra css ref held by bios and utilize the blkg ref > > The major difference with v2 is that error handling on blkg creation > and association failure is handled more gracefully. Rather than having > the complex logic to fallback to root, failures walk up the blkg tree. > This seems more natural and less prone to error with the many possible > failure scenarios. > > Additionally, there are fixes for kbuild errors and some key details > overlooked by me in the first series that were pointed out in review. > > Modified from the first patchset: > First, both blk-throttle and blk-iolatency rely on blkg association > to enable their policies. Rather than each policy (and future policies) > implement this logic independently, this consolidates it such that > all bios are tagged with a blkg. > > Second, with the addition of always having a blkg reference, the blkcg > can now be referenced through it rather than maintaining an additional > pointer and reference. So let's clean this up. > > [1] https://lore.kernel.org/lkml/20180831015356.69796-1-dennisszhou@xxxxxxxxx/T > > This patchset contains the following 12 patches: > 0001-blkcg-fix-ref-count-issue-with-bio_blkcg-using-task_.patch > 0002-blkcg-update-blkg_lookup_create-to-do-locking.patch > 0003-blkcg-convert-blkg_lookup_create-to-find-closest-blk.patch > 0004-blkcg-always-associate-a-bio-with-a-blkg.patch > 0005-blkcg-consolidate-bio_issue_init-to-be-a-part-of-cor.patch > 0006-blkcg-associate-a-blkg-for-pages-being-evicted-by-sw.patch > 0007-blkcg-associate-writeback-bios-with-a-blkg.patch > 0008-blkcg-remove-bio-bi_css-and-instead-use-bio-bi_blkg.patch > 0009-blkcg-remove-additional-reference-to-the-css.patch > 0010-blkcg-cleanup-and-make-blk_get_rl-use-blkg_lookup_cr.patch > 0011-blkcg-change-blkg-reference-counting-to-use-percpu_r.patch > 0012-blkcg-rename-blkg_try_get-to-blkg_tryget.patch > > This patchset is on top of axboe#for-4.20/block 902d53914f64. > > diffstats below: > > Dennis Zhou (Facebook) (12): > blkcg: fix ref count issue with bio_blkcg using task_css > blkcg: update blkg_lookup_create to do locking > blkcg: convert blkg_lookup_create to find closest blkg > blkcg: always associate a bio with a blkg > blkcg: consolidate bio_issue_init to be a part of core > blkcg: associate a blkg for pages being evicted by swap > blkcg: associate writeback bios with a blkg > blkcg: remove bio->bi_css and instead use bio->bi_blkg > blkcg: remove additional reference to the css > blkcg: cleanup and make blk_get_rl use blkg_lookup_create > blkcg: change blkg reference counting to use percpu_ref > blkcg: rename blkg_try_get to blkg_tryget > > Documentation/admin-guide/cgroup-v2.rst | 8 +- > block/bfq-cgroup.c | 4 +- > block/bfq-iosched.c | 2 +- > block/bio.c | 158 ++++++++++++++++-------- > block/blk-cgroup.c | 123 ++++++++++++------ > block/blk-iolatency.c | 26 +--- > block/blk-throttle.c | 13 +- > block/bounce.c | 4 +- > block/cfq-iosched.c | 4 +- > drivers/block/loop.c | 5 +- > drivers/md/raid0.c | 2 +- > fs/buffer.c | 10 +- > fs/ext4/page-io.c | 2 +- > include/linux/bio.h | 23 ++-- > include/linux/blk-cgroup.h | 145 +++++++++++++++------- > include/linux/blk_types.h | 1 - > include/linux/cgroup.h | 2 + > include/linux/writeback.h | 5 +- > kernel/cgroup/cgroup.c | 48 +++++-- > kernel/trace/blktrace.c | 4 +- > mm/page_io.c | 2 +- > 21 files changed, 381 insertions(+), 210 deletions(-) > > Thanks, > Dennis I reran some basic test again for sanity and it seems to be fine on my end. There are at least acks, and some reviewed-by's on the series. Is there anything else you think needs to be done before we let this bake in for-4.20/for-next? Thanks, Dennis