| Message ID | 1432329245-5844-30-git-send-email-tj@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 22-05-15 17:13:43, Tejun Heo wrote: > Now that bdi layer can handle per-blkcg bdi_writeback_congested state, > blk_{set|clear}_congested() can propagate non-root blkcg congestion > state to them. > > This can be easily achieved by disabling the root_rl tests in > blk_{set|clear}_congested(). Note that we still need those tests when > !CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg > wb's congestion state for events happening on other blkcgs. > > v2: Updated for bdi_writeback_congested. Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.com> Honza > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Jan Kara <jack@suse.cz> > Cc: Vivek Goyal <vgoyal@redhat.com> > --- > block/blk-core.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index b457c4f..cf6974e 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -65,23 +65,26 @@ static struct workqueue_struct *kblockd_workqueue; > > static void blk_clear_congested(struct request_list *rl, int sync) > { > - if (rl != &rl->q->root_rl) > - return; > #ifdef CONFIG_CGROUP_WRITEBACK > clear_wb_congested(rl->blkg->wb_congested, sync); > #else > - clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); > + /* > + * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't > + * flip its congestion state for events on other blkcgs. > + */ > + if (rl == &rl->q->root_rl) > + clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); > #endif > } > > static void blk_set_congested(struct request_list *rl, int sync) > { > - if (rl != &rl->q->root_rl) > - return; > #ifdef CONFIG_CGROUP_WRITEBACK > set_wb_congested(rl->blkg->wb_congested, sync); > #else > - set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); > + /* see blk_clear_congested() */ > + if (rl == &rl->q->root_rl) > + set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); > #endif > } > > -- > 2.4.0 >
diff --git a/block/blk-core.c b/block/blk-core.c index b457c4f..cf6974e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -65,23 +65,26 @@ static struct workqueue_struct *kblockd_workqueue; static void blk_clear_congested(struct request_list *rl, int sync) { - if (rl != &rl->q->root_rl) - return; #ifdef CONFIG_CGROUP_WRITEBACK clear_wb_congested(rl->blkg->wb_congested, sync); #else - clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); + /* + * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't + * flip its congestion state for events on other blkcgs. + */ + if (rl == &rl->q->root_rl) + clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); #endif } static void blk_set_congested(struct request_list *rl, int sync) { - if (rl != &rl->q->root_rl) - return; #ifdef CONFIG_CGROUP_WRITEBACK set_wb_congested(rl->blkg->wb_congested, sync); #else - set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); + /* see blk_clear_congested() */ + if (rl == &rl->q->root_rl) + set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); #endif }
Now that bdi layer can handle per-blkcg bdi_writeback_congested state, blk_{set|clear}_congested() can propagate non-root blkcg congestion state to them. This can be easily achieved by disabling the root_rl tests in blk_{set|clear}_congested(). Note that we still need those tests when !CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg wb's congestion state for events happening on other blkcgs. v2: Updated for bdi_writeback_congested. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> --- block/blk-core.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)