Re: [PATCH -V8 10/16] hugetlb/cgroup: Add the cgroup pointer to page lru
From: Konrad Rzeszutek Wilk <hidden>
Date: 2012-06-09 11:14:17
Also in:
linux-mm, lkml
On Sat, Jun 09, 2012 at 02:29:55PM +0530, Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V" <redacted> Add the hugetlb cgroup pointer to 3rd page lru.next. This limit the usage to hugetlb cgroup to only hugepages with 3 or more normal pages. I guess that is an acceptable limitation.
Can you explain in a bit more detail the reasoning behind this please? Either in the code in the hugetlb_cgroup_from_page or in the git commit (or better - in both).
quoted hunk ↗ jump to hunk
Signed-off-by: Aneesh Kumar K.V <redacted> --- include/linux/hugetlb_cgroup.h | 31 +++++++++++++++++++++++++++++++ mm/hugetlb.c | 4 ++++ 2 files changed, 35 insertions(+)diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index 5794be4..ceff1d5 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h@@ -26,6 +26,26 @@ struct hugetlb_cgroup { }; #ifdef CONFIG_CGROUP_HUGETLB_RES_CTLR +static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) +{ + if (!PageHuge(page)) + return NULL; + if (compound_order(page) < 3) + return NULL; + return (struct hugetlb_cgroup *)page[2].lru.next; +} + +static inline +int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) +{ + if (!PageHuge(page)) + return -1; + if (compound_order(page) < 3) + return -1; + page[2].lru.next = (void *)h_cg; + return 0; +} + static inline bool hugetlb_cgroup_disabled(void) { if (hugetlb_subsys.disabled)@@ -43,6 +63,17 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg); #else +static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) +{ + return NULL; +} + +static inline +int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) +{ + return 0; +} + static inline bool hugetlb_cgroup_disabled(void) { return true;diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e899a2d..1ca2d8f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c@@ -28,6 +28,7 @@ #include <linux/io.h> #include <linux/hugetlb.h> +#include <linux/hugetlb_cgroup.h> #include <linux/node.h> #include "internal.h"@@ -591,6 +592,7 @@ static void update_and_free_page(struct hstate *h, struct page *page) 1 << PG_active | 1 << PG_reserved | 1 << PG_private | 1 << PG_writeback); } + BUG_ON(hugetlb_cgroup_from_page(page)); set_compound_page_dtor(page, NULL); set_page_refcounted(page); arch_release_hugepage(page);@@ -643,6 +645,7 @@ static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) INIT_LIST_HEAD(&page->lru); set_compound_page_dtor(page, free_huge_page); spin_lock(&hugetlb_lock); + set_hugetlb_cgroup(page, NULL); h->nr_huge_pages++; h->nr_huge_pages_node[nid]++; spin_unlock(&hugetlb_lock);@@ -892,6 +895,7 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid) INIT_LIST_HEAD(&page->lru); r_nid = page_to_nid(page); set_compound_page_dtor(page, free_huge_page); + set_hugetlb_cgroup(page, NULL); /* * We incremented the global counters already */-- 1.7.10 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo-Bw31MaZKKs0EbZ0PF+XxCw@public.gmane.org For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org"> email-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org </a>