Re: [PATCH -V8 11/16] hugetlb/cgroup: Add charge/uncharge routines for hugetlb cgroup
From: Michal Hocko <hidden>
Date: 2012-06-11 08:38:13
Also in:
linux-mm, lkml
On Sat 09-06-12 14:29:56, Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V" <redacted> This patchset add the charge and uncharge routines for hugetlb cgroup. This will be used in later patches when we allocate/free HugeTLB pages.
Please describe the locking rules.
quoted hunk ↗ jump to hunk
Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/hugetlb_cgroup.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+)diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 20a32c5..48efd5a 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c@@ -105,6 +105,93 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup) return -EBUSY; } +int hugetlb_cgroup_charge_page(int idx, unsigned long nr_pages, + struct hugetlb_cgroup **ptr)
Missing doc.
+{
+ int ret = 0;
+ struct res_counter *fail_res;
+ struct hugetlb_cgroup *h_cg = NULL;
+ unsigned long csize = nr_pages * PAGE_SIZE;
+
+ if (hugetlb_cgroup_disabled())
+ goto done;
+ /*
+ * We don't charge any cgroup if the compound page have less
+ * than 3 pages.
+ */
+ if (hstates[idx].order < 2)
+ goto done;huge_page_order here? Not that important because we are using order in the code directly at many places but easier for grep and maybe worth a separate clean up patch.
+again:
+ rcu_read_lock();
+ h_cg = hugetlb_cgroup_from_task(current);
+ if (!h_cg)
+ h_cg = root_h_cgroup;
+
+ if (!css_tryget(&h_cg->css)) {
+ rcu_read_unlock();
+ goto again;
+ }
+ rcu_read_unlock();
+
+ ret = res_counter_charge(&h_cg->hugepage[idx], csize, &fail_res);
+ css_put(&h_cg->css);
+done:
+ *ptr = h_cg;
+ return ret;
+}
+
+void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
+ struct hugetlb_cgroup *h_cg,
+ struct page *page)
+{
+ if (hugetlb_cgroup_disabled() || !h_cg)
+ return;
+
+ spin_lock(&hugetlb_lock);
+ if (hugetlb_cgroup_from_page(page)) {How can this happen? Is it possible that two CPUs are trying to charge one page?
+ hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg);
+ goto done;
+ }
+ set_hugetlb_cgroup(page, h_cg);
+done:
+ spin_unlock(&hugetlb_lock);
+ return;
+}
+
+void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
+ struct page *page)
+{
+ struct hugetlb_cgroup *h_cg;
+ unsigned long csize = nr_pages * PAGE_SIZE;
+
+ if (hugetlb_cgroup_disabled())
+ return;
+
+ spin_lock(&hugetlb_lock);
+ h_cg = hugetlb_cgroup_from_page(page);
+ if (unlikely(!h_cg)) {
+ spin_unlock(&hugetlb_lock);
+ return;
+ }
+ set_hugetlb_cgroup(page, NULL);
+ spin_unlock(&hugetlb_lock);
+
+ res_counter_uncharge(&h_cg->hugepage[idx], csize);
+ return;
+}
+
+void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
+ struct hugetlb_cgroup *h_cg)
+{Really worth a separate function to do the same tests again? Will have a look at the follow up patches. It would be much easier if the functions were used in the same patch...
+ unsigned long csize = nr_pages * PAGE_SIZE;
+
+ if (hugetlb_cgroup_disabled() || !h_cg)
+ return;
+
+ res_counter_uncharge(&h_cg->hugepage[idx], csize);
+ return;
+}
+
struct cgroup_subsys hugetlb_subsys = {
.name = "hugetlb",
.create = hugetlb_cgroup_create,
--
1.7.10-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic