Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6060bcdc authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
Browse files

rhashtable: reorganize struct rhashtable layout 



While under frags DDOS I noticed unfortunate false sharing between
@nelems and @params.automatic_shrinking

Move @nelems at the end of struct rhashtable so that first cache line
is shared between all cpus, because almost never dirtied.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
(cherry picked from commit e5d672a0780d9e7118caad4c171ec88b8299398d)
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cbc45497

include/linux/rhashtable.h

+2 −2
Original line number Original line Diff line number Diff line
@@ -138,7 +138,6 @@ struct rhashtable_params { 
/**

/**

 * struct rhashtable - Hash table handle

 * struct rhashtable - Hash table handle

 * @tbl: Bucket table

 * @tbl: Bucket table

 * @nelems: Number of elements in table

 * @key_len: Key length for hashfn

 * @key_len: Key length for hashfn

 * @elasticity: Maximum chain length before rehash

 * @elasticity: Maximum chain length before rehash

 * @p: Configuration parameters

 * @p: Configuration parameters
@@ -146,10 +145,10 @@ struct rhashtable_params { 
 * @run_work: Deferred worker to expand/shrink asynchronously

 * @run_work: Deferred worker to expand/shrink asynchronously

 * @mutex: Mutex to protect current/future table swapping

 * @mutex: Mutex to protect current/future table swapping

 * @lock: Spin lock to protect walker list

 * @lock: Spin lock to protect walker list

 * @nelems: Number of elements in table

 */

 */

struct rhashtable {

struct rhashtable {

	struct bucket_table __rcu	*tbl;

	struct bucket_table __rcu	*tbl;

	atomic_t			nelems;

	unsigned int			key_len;

	unsigned int			key_len;

	unsigned int			elasticity;

	unsigned int			elasticity;

	struct rhashtable_params	p;

	struct rhashtable_params	p;
@@ -157,6 +156,7 @@ struct rhashtable { 
	struct work_struct		run_work;

	struct work_struct		run_work;

	struct mutex                    mutex;

	struct mutex                    mutex;

	spinlock_t			lock;

	spinlock_t			lock;

	atomic_t			nelems;

};

};





/**

/**