From 075a61d07a8eca2fe980acd94105ed5d6429c55d Mon Sep 17 00:00:00 2001 From: Mina Almasry Date: Wed, 1 Apr 2020 21:11:28 -0700 Subject: hugetlb_cgroup: add accounting for shared mappings For shared mappings, the pointer to the hugetlb_cgroup to uncharge lives in the resv_map entries, in file_region->reservation_counter. After a call to region_chg, we charge the approprate hugetlb_cgroup, and if successful, we pass on the hugetlb_cgroup info to a follow up region_add call. When a file_region entry is added to the resv_map via region_add, we put the pointer to that cgroup in file_region->reservation_counter. If charging doesn't succeed, we report the error to the caller, so that the kernel fails the reservation. On region_del, which is when the hugetlb memory is unreserved, we also uncharge the file_region->reservation_counter. [akpm@linux-foundation.org: forward declare struct file_region] Signed-off-by: Mina Almasry Signed-off-by: Andrew Morton Reviewed-by: Mike Kravetz Cc: David Rientjes Cc: Greg Thelen Cc: Mike Kravetz Cc: Sandipan Das Cc: Shakeel Butt Cc: Shuah Khan Link: http://lkml.kernel.org/r/20200211213128.73302-5-almasrymina@google.com Signed-off-by: Linus Torvalds --- mm/hugetlb_cgroup.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'mm/hugetlb_cgroup.c') diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 372238257baa..c2d7ae6cabd1 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -391,6 +391,21 @@ void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start, css_put(resv->css); } +void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv, + struct file_region *rg, + unsigned long nr_pages) +{ + if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages) + return; + + if (rg->reservation_counter && resv->pages_per_hpage && nr_pages > 0 && + !resv->reservation_counter) { + page_counter_uncharge(rg->reservation_counter, + nr_pages * resv->pages_per_hpage); + css_put(rg->css); + } +} + enum { RES_USAGE, RES_RSVD_USAGE, -- cgit v1.2.3