From: Vasily Averin <vvs@xxxxxxxxxxxxx> Subject: memcg: enable accounting for pollfd and select bits arrays User can call select/poll system calls with a large number of assigned file descriptors and force kernel to allocate up to several pages of memory till end of these sleeping system calls. We have here long-living unaccounted per-task allocations. It makes sense to account for these allocations to restrict the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/56e31cb5-6e1e-bdba-d7ca-be64b9842363@xxxxxxxxxxxxx Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Andrei Vagin <avagin@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Christian Brauner <christian.brauner@xxxxxxxxxx> Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx> Cc: Jeff Layton <jlayton@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Jiri Slaby <jirislaby@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Cc: Serge Hallyn <serge@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Yutian Yang <nglaive@xxxxxxxxx> Cc: Zefan Li <lizefan.x@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/select.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/select.c~memcg-enable-accounting-for-pollfd-and-select-bits-arrays +++ a/fs/select.c @@ -655,7 +655,7 @@ int core_sys_select(int n, fd_set __user goto out_nofds; alloc_size = 6 * size; - bits = kvmalloc(alloc_size, GFP_KERNEL); + bits = kvmalloc(alloc_size, GFP_KERNEL_ACCOUNT); if (!bits) goto out_nofds; } @@ -1000,7 +1000,7 @@ static int do_sys_poll(struct pollfd __u len = min(todo, POLLFD_PER_PAGE); walk = walk->next = kmalloc(struct_size(walk, entries, len), - GFP_KERNEL); + GFP_KERNEL_ACCOUNT); if (!walk) { err = -ENOMEM; goto out_fds; _
