net: convert TCP/DCCP ehash rwlocks to spinlocks
Now TCP & DCCP use RCU lookups, we can convert ehash rwlocks to spinlocks.
/proc/net/tcp and other seq_file 'readers' can safely be converted to 'writers'.
This should speedup writers, since spin_lock()/spin_unlock()
only use one atomic operation instead of two for write_lock()/write_unlock()
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 62d2dd0d..28b3ee3e 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -116,7 +116,7 @@
* TIME_WAIT sockets use a separate chain (twchain).
*/
struct inet_ehash_bucket *ehash;
- rwlock_t *ehash_locks;
+ spinlock_t *ehash_locks;
unsigned int ehash_size;
unsigned int ehash_locks_mask;
@@ -152,7 +152,7 @@
return &hashinfo->ehash[hash & (hashinfo->ehash_size - 1)];
}
-static inline rwlock_t *inet_ehash_lockp(
+static inline spinlock_t *inet_ehash_lockp(
struct inet_hashinfo *hashinfo,
unsigned int hash)
{
@@ -177,16 +177,16 @@
size = 4096;
if (sizeof(rwlock_t) != 0) {
#ifdef CONFIG_NUMA
- if (size * sizeof(rwlock_t) > PAGE_SIZE)
- hashinfo->ehash_locks = vmalloc(size * sizeof(rwlock_t));
+ if (size * sizeof(spinlock_t) > PAGE_SIZE)
+ hashinfo->ehash_locks = vmalloc(size * sizeof(spinlock_t));
else
#endif
- hashinfo->ehash_locks = kmalloc(size * sizeof(rwlock_t),
+ hashinfo->ehash_locks = kmalloc(size * sizeof(spinlock_t),
GFP_KERNEL);
if (!hashinfo->ehash_locks)
return ENOMEM;
for (i = 0; i < size; i++)
- rwlock_init(&hashinfo->ehash_locks[i]);
+ spin_lock_init(&hashinfo->ehash_locks[i]);
}
hashinfo->ehash_locks_mask = size - 1;
return 0;
@@ -197,7 +197,7 @@
if (hashinfo->ehash_locks) {
#ifdef CONFIG_NUMA
unsigned int size = (hashinfo->ehash_locks_mask + 1) *
- sizeof(rwlock_t);
+ sizeof(spinlock_t);
if (size > PAGE_SIZE)
vfree(hashinfo->ehash_locks);
else
