Re: [PATCH -V8 12/16] hugetlb/cgroup: Add support for cgroup removal
From: Kamezawa Hiroyuki <hidden>
Date: 2012-06-12 08:25:26
Also in:
linux-mm, lkml
(2012/06/09 17:59), Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V"<redacted> This patch add support for cgroup removal. If we don't have parent cgroup, the charges are moved to root cgroup. Signed-off-by: Aneesh Kumar K.V<redacted>
I'm sorry if already pointed out....
quoted hunk ↗ jump to hunk
--- mm/hugetlb_cgroup.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 79 insertions(+), 2 deletions(-)diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 48efd5a..9458fe3 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c@@ -99,10 +99,87 @@ static void hugetlb_cgroup_destroy(struct cgroup *cgroup) kfree(h_cgroup); } + +static int hugetlb_cgroup_move_parent(int idx, struct cgroup *cgroup, + struct page *page) +{ + int csize; + struct res_counter *counter; + struct res_counter *fail_res; + struct hugetlb_cgroup *page_hcg; + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); + struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(cgroup); + + if (!get_page_unless_zero(page)) + goto out;
It seems this doesn't necessary...this is under hugetlb_lock().
+
+ page_hcg = hugetlb_cgroup_from_page(page);
+ /*
+ * We can have pages in active list without any cgroup
+ * ie, hugepage with less than 3 pages. We can safely
+ * ignore those pages.
+ */
+ if (!page_hcg || page_hcg != h_cg)
+ goto err_out;
+
+ csize = PAGE_SIZE<< compound_order(page);
+ if (!parent) {
+ parent = root_h_cgroup;
+ /* root has no limit */
+ res_counter_charge_nofail(&parent->hugepage[idx],
+ csize,&fail_res);^^^ space ?
+ }
+ counter =&h_cg->hugepage[idx];
+ res_counter_uncharge_until(counter, counter->parent, csize);
+
+ set_hugetlb_cgroup(page, parent);
+err_out:
+ put_page(page);
+out:
+ return 0;
+}
+
+/*
+ * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
+ * the parent cgroup.
+ */
static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
{
- /* We will add the cgroup removal support in later patches */
- return -EBUSY;
+ struct hstate *h;
+ struct page *page;
+ int ret = 0, idx = 0;
+
+ do {
+ if (cgroup_task_count(cgroup) ||
+ !list_empty(&cgroup->children)) {
+ ret = -EBUSY;
+ goto out;
+ }+ /*
+ * If the task doing the cgroup_rmdir got a signal
+ * we don't really need to loop till the hugetlb resource
+ * usage become zero.
+ */
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ goto out;
+ }I'll post a patch to remove this check from memcg because memcg's rmdir always succeed now. So, could you remove this ?
+ for_each_hstate(h) {
+ spin_lock(&hugetlb_lock);
+ list_for_each_entry(page,&h->hugepage_activelist, lru) {
+ ret = hugetlb_cgroup_move_parent(idx, cgroup, page);
+ if (ret) {When 'ret' should be !0 ? If hugetlb_cgroup_move_parent() always returns 0, the check will not be necessary. Thanks, -Kame
+ spin_unlock(&hugetlb_lock); + goto out; + } + } + spin_unlock(&hugetlb_lock); + idx++; + } + cond_resched(); + } while (hugetlb_cgroup_have_usage(cgroup)); +out: + return ret; } int hugetlb_cgroup_charge_page(int idx, unsigned long nr_pages,