diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-10-10 12:30:03 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 09:13:25 +0200 |
| commit | 6060bcdcffaba68c3ff158a88faab6df27210ffc (patch) | |
| tree | 5a2225b1382fdd96cc45acc5ec6624247618a644 | |
| parent | cbc45497b39c4626adaeca2a409588f19ae19e34 (diff) | |
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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e5d672a0780d9e7118caad4c171ec88b8299398d)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/rhashtable.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 85d1ffc90285..4421e5ccb092 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -138,7 +138,6 @@ struct rhashtable_params { /** * struct rhashtable - Hash table handle * @tbl: Bucket table - * @nelems: Number of elements in table * @key_len: Key length for hashfn * @elasticity: Maximum chain length before rehash * @p: Configuration parameters @@ -146,10 +145,10 @@ struct rhashtable_params { * @run_work: Deferred worker to expand/shrink asynchronously * @mutex: Mutex to protect current/future table swapping * @lock: Spin lock to protect walker list + * @nelems: Number of elements in table */ struct rhashtable { struct bucket_table __rcu *tbl; - atomic_t nelems; unsigned int key_len; unsigned int elasticity; struct rhashtable_params p; @@ -157,6 +156,7 @@ struct rhashtable { struct work_struct run_work; struct mutex mutex; spinlock_t lock; + atomic_t nelems; }; /** |