diff options
author | Mina Almasry <almasrymina@google.com> | 2020-04-02 07:11:28 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-02 19:35:32 +0300 |
commit | 075a61d07a8eca2fe980acd94105ed5d6429c55d (patch) | |
tree | f6dee0085978acc39344d84b464c178477a46645 /include/linux/hugetlb.h | |
parent | 0db9d74ed8845a32a68a5bb7323fa59f92767eb5 (diff) | |
download | linux-075a61d07a8eca2fe980acd94105ed5d6429c55d.tar.xz |
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 <almasrymina@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Link: http://lkml.kernel.org/r/20200211213128.73302-5-almasrymina@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/hugetlb.h')
-rw-r--r-- | include/linux/hugetlb.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 8f8c0b915fbb..219962c9517e 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -57,6 +57,41 @@ struct resv_map { struct cgroup_subsys_state *css; #endif }; + +/* + * Region tracking -- allows tracking of reservations and instantiated pages + * across the pages in a mapping. + * + * The region data structures are embedded into a resv_map and protected + * by a resv_map's lock. The set of regions within the resv_map represent + * reservations for huge pages, or huge pages that have already been + * instantiated within the map. The from and to elements are huge page + * indicies into the associated mapping. from indicates the starting index + * of the region. to represents the first index past the end of the region. + * + * For example, a file region structure with from == 0 and to == 4 represents + * four huge pages in a mapping. It is important to note that the to element + * represents the first element past the end of the region. This is used in + * arithmetic as 4(to) - 0(from) = 4 huge pages in the region. + * + * Interval notation of the form [from, to) will be used to indicate that + * the endpoint from is inclusive and to is exclusive. + */ +struct file_region { + struct list_head link; + long from; + long to; +#ifdef CONFIG_CGROUP_HUGETLB + /* + * On shared mappings, each reserved region appears as a struct + * file_region in resv_map. These fields hold the info needed to + * uncharge each reservation. + */ + struct page_counter *reservation_counter; + struct cgroup_subsys_state *css; +#endif +}; + extern struct resv_map *resv_map_alloc(void); void resv_map_release(struct kref *ref); |