Re: [PATCH v3 4/8] cgroup: rstat: support cgroup1
From: Michal Koutný <hidden>
Date: 2021-02-17 17:43:38
Also in:
linux-mm, lkml
Hello. On Tue, Feb 09, 2021 at 11:33:00AM -0500, Johannes Weiner [off-list ref] wrote:
quoted hunk ↗ jump to hunk
@@ -1971,10 +1978,14 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) if (ret) goto destroy_root; - ret = rebind_subsystems(root, ss_mask); + ret = cgroup_rstat_init(root_cgrp);
Would it make sense to do cgroup_rstat_init() only if there's a subsys in ss_mask that makes use of rstat? (On legacy systems there could be individual hierarchy for each controller so the rstat space can be saved.)
quoted hunk ↗ jump to hunk
@@ -5159,11 +5170,9 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, if (ret) goto out_free_cgrp; - if (cgroup_on_dfl(parent)) { - ret = cgroup_rstat_init(cgrp); - if (ret) - goto out_cancel_ref; - } + ret = cgroup_rstat_init(cgrp);
And here do cgroup_rstat_init() only when parent has it.
quoted hunk ↗ jump to hunk
@@ -285,8 +285,6 @@ void __init cgroup_rstat_boot(void) for_each_possible_cpu(cpu) raw_spin_lock_init(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); - - BUG_ON(cgroup_rstat_init(&cgrp_dfl_root.cgrp)); }
Regardless of the suggestion above, this removal obsoletes the comment
cgroup_rstat_init:
int cpu;
- /* the root cgrp has rstat_cpu preallocated */
if (!cgrp->rstat_cpu) {
cgrp->rstat_cpu = alloc_percpu(struct cgroup_rstat_cpu);
Regards,
Michal Attachments
- signature.asc [application/pgp-signature] 833 bytes