[PATCH stable 4.9 v2 15/29] rhashtable: reorganize struct rhashtable layout
From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2018-10-11 02:54:26
Also in:
stable
Subsystem:
rhashtable, the rest · Maintainers:
Thomas Graf, Herbert Xu, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> 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) --- include/linux/rhashtable.h | 4 ++-- 1 file 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; }; /**
--
2.17.1