diff options
| author | Minchan Kim <minchan@kernel.org> | 2021-11-18 15:00:08 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-24 13:55:16 +0100 |
| commit | 393c3714081a53795bbff0e985d24146def6f57f (patch) | |
| tree | 188134895692753a0862a1cbd9a8466d56a4245b /include/linux/kernfs.h | |
| parent | 136057256686de39cc3a07c2e39ef6bc43003ff6 (diff) | |
kernfs: switch global kernfs_rwsem lock to per-fs lock
The kernfs implementation has big lock granularity(kernfs_rwsem) so
every kernfs-based(e.g., sysfs, cgroup) fs are able to compete the
lock. It makes trouble for some cases to wait the global lock
for a long time even though they are totally independent contexts
each other.
A general example is process A goes under direct reclaim with holding
the lock when it accessed the file in sysfs and process B is waiting
the lock with exclusive mode and then process C is waiting the lock
until process B could finish the job after it gets the lock from
process A.
This patch switches the global kernfs_rwsem to per-fs lock, which
put the rwsem into kernfs_root.
Suggested-by: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/r/20211118230008.2679780-1-minchan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/kernfs.h')
| -rw-r--r-- | include/linux/kernfs.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 3ccce6f24548..9f650986a81b 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -16,6 +16,7 @@ #include <linux/atomic.h> #include <linux/uidgid.h> #include <linux/wait.h> +#include <linux/rwsem.h> struct file; struct dentry; @@ -197,6 +198,7 @@ struct kernfs_root { struct list_head supers; wait_queue_head_t deactivate_waitq; + struct rw_semaphore kernfs_rwsem; }; struct kernfs_open_file { |