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* [PATCH v3 0/2] kernfs: use hashed mutex and spinlock in place of global ones
@ 2022-01-13 10:42 Imran Khan
  2022-01-13 10:42 ` [PATCH v3 1/2] " Imran Khan
                   ` (2 more replies)
  0 siblings, 3 replies; 11+ messages in thread
From: Imran Khan @ 2022-01-13 10:42 UTC (permalink / raw)
  To: tj, gregkh; +Cc: linux-kernel

Reduce contention around global locks used in kernfs.

PATCH-1: Make global kernfs_open_file_mutex and kernfs_open_node_lock
	 hashed locks, where address of a kernfs_node acts as hash key.
	 This results in kernfs_node objects, whose address give the
	 different hash value, using different kernfs_open_file_mutex
	 and kernfs_open_node_lock rather than all kernfs_node objects
	 using the same kernfs_open_file_mutex and kernfs_open_node_lock
	 as was the case earlier.

PATCH-2: Use a hashed rw_semaphore to access permissions, so that we can
	 avoid contention around global per-fs rw_semaphore, seen if
	 multiple applications are executing inode_permission and
	 walk_component in parallel when trying to open sysfs file(s).

------------------------------------------------------------------

Changes since v2:
 - Remove RFC tag
 - Use hashed locks rather than using per kernfs_node specific lock
   (Suggested by Tejun Heo <tj@kernel.org>)
   

Imran Khan (2):
  kernfs: use hashed mutex and spinlock in place of global ones.
  kernfs: Reduce contention around global per-fs kernfs_rwsem.

 fs/kernfs/dir.c             |  8 +++++
 fs/kernfs/file.c            | 65 ++++++++++++++++-----------------
 fs/kernfs/inode.c           | 35 ++++++++++++------
 fs/kernfs/kernfs-internal.h | 71 +++++++++++++++++++++++++++++++++++++
 fs/kernfs/mount.c           | 11 ++++++
 5 files changed, 146 insertions(+), 44 deletions(-)


base-commit: a70bf4a85b43cb952bd39dd948b103b1b3eb2cf8
-- 
2.30.2


^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2022-02-02 15:10 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-13 10:42 [PATCH v3 0/2] kernfs: use hashed mutex and spinlock in place of global ones Imran Khan
2022-01-13 10:42 ` [PATCH v3 1/2] " Imran Khan
2022-01-13 16:37   ` Tejun Heo
2022-01-13 10:42 ` [PATCH v3 2/2] kernfs: Reduce contention around global per-fs kernfs_rwsem Imran Khan
2022-01-13 10:58   ` Greg KH
2022-01-13 16:42   ` Tejun Heo
2022-01-14 17:08     ` Imran Khan
2022-01-14 17:44       ` Tejun Heo
2022-02-02 15:10     ` Imran Khan
2022-01-25  2:55   ` [kernfs] 8652224976: WARNING:at_kernel/locking/rwsem.c:#up_write kernel test robot
2022-01-13 10:57 ` [PATCH v3 0/2] kernfs: use hashed mutex and spinlock in place of global ones Greg KH

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