projects/linux·commit d447ea2f

cgroups: add the trigger callback to struct cftype

d447ea2f · Pavel Emelyanov <[email protected]> · 2008-04-29 01:00:08 -07:00

Trigger callback can be used to receive a kick-up from the user space.  The
string written is ignored.

The cftype->private is used for multiplexing events.

Signed-off-by: Pavel Emelyanov <[email protected]>
Acked-by: Paul Menage <[email protected]>
Acked-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Balbir Singh <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
d447ea2f30ec60370ddb99a668e5ac12995f043d
Parents
46ae220b

Changes

2 files changed · +12 −0

FileStatusAddDelContent
include/linux/cgroup.hmodified+8−0View file
kernel/cgroup.cmodified+4−0View file

include/linux/cgroup.h

View file
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 785a01c..2d1d151 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -243,6 +243,14 @@ struct cftype {
*/
int (*write_s64) (struct cgroup *cgrp, struct cftype *cft, s64 val);
+ /*
+ * trigger() callback can be used to get some kick from the
+ * userspace, when the actual string written is not important
+ * at all. The private field can be used to determine the
+ * kick type for multiplexing.
+ */
+ int (*trigger)(struct cgroup *cgrp, unsigned int event);
+
int (*release) (struct inode *inode, struct file *file);
};

kernel/cgroup.c

View file
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 436e26f..7c8cc51 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1410,6 +1410,10 @@ static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
return cft->write(cgrp, cft, file, buf, nbytes, ppos);
if (cft->write_u64 || cft->write_s64)
return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos);
+ if (cft->trigger) {
+ int ret = cft->trigger(cgrp, (unsigned int)cft->private);
+ return ret ? ret : nbytes;
+ }
return -EINVAL;
}