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authorJohannes Weiner <hannes@cmpxchg.org>2019-03-06 02:45:48 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-06 08:07:17 +0300
commitdc50537bdd1a0804fa2cbc990565ee9a944e66fa (patch)
tree53612bc32abbad48ec53a961f866b6244bc02bf9 /include/linux/cgroup-defs.h
parent147e1a97c4a0bdd43f55a582a9416bb9092563a9 (diff)
downloadlinux-dc50537bdd1a0804fa2cbc990565ee9a944e66fa.tar.xz
kernel: cgroup: add poll file operation
Cgroup has a standardized poll/notification mechanism for waking all pollers on all fds when a filesystem node changes. To allow polling for custom events, add a .poll callback that can override the default. This is in preparation for pollable cgroup pressure files which have per-fd trigger configurations. Link: http://lkml.kernel.org/r/20190124211518.244221-3-surenb@google.com Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/cgroup-defs.h')
-rw-r--r--include/linux/cgroup-defs.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 8fcbae1b8db0..aad3babef007 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -32,6 +32,7 @@ struct kernfs_node;
struct kernfs_ops;
struct kernfs_open_file;
struct seq_file;
+struct poll_table_struct;
#define MAX_CGROUP_TYPE_NAMELEN 32
#define MAX_CGROUP_ROOT_NAMELEN 64
@@ -574,6 +575,9 @@ struct cftype {
ssize_t (*write)(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off);
+ __poll_t (*poll)(struct kernfs_open_file *of,
+ struct poll_table_struct *pt);
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lock_class_key lockdep_key;
#endif