blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
cgroup is trying to make interface consistent across different
controllers. For weight based resource control, the knob should have
the range [1, 10000] and default to 100. This patch updates
cfq-iosched so that the weight range conforms. The internal
calculations have enough range and the widening of the weight range
shouldn't cause any problem.
* blkcg_policy->cpd_bind_fn() is added. If present, this is invoked
when blkcg is attached to a hierarchy.
* cfq_cpd_init() is updated to use the new default value on the
unified hierarchy.
* cfq_cpd_bind() callback is implemented to clear per-blkg configs and
apply the default config matching the hierarchy type.
* cfqd->root_group->[leaf_]weight initialization in cfq_init_queue()
is moved into !CONFIG_CFQ_GROUP_IOSCHED block. cfq_cpd_bind() is
now responsible for initializing the initial weights when blkcg is
enabled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 88bdb73..ac8370c 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1143,11 +1143,32 @@
return ret;
}
+static void blkcg_bind(struct cgroup_subsys_state *root_css)
+{
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg *blkcg;
+
+ if (!pol || !pol->cpd_bind_fn)
+ continue;
+
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node)
+ if (blkcg->cpd[pol->plid])
+ pol->cpd_bind_fn(blkcg->cpd[pol->plid]);
+ }
+ mutex_unlock(&blkcg_pol_mutex);
+}
+
struct cgroup_subsys io_cgrp_subsys = {
.css_alloc = blkcg_css_alloc,
.css_offline = blkcg_css_offline,
.css_free = blkcg_css_free,
.can_attach = blkcg_can_attach,
+ .bind = blkcg_bind,
.dfl_cftypes = blkcg_files,
.legacy_cftypes = blkcg_legacy_files,
.legacy_name = "blkio",