xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls

Browse Source 
RCU was added to UDP lookups, using a fast infrastructure :
- sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the
  price of call_rcu() at freeing time.
- hlist_nulls permits to use few memory barriers.

This patch uses same infrastructure for TCP/DCCP established
and timewait sockets.

Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications
using short lived TCP connections. A followup patch, converting
rwlocks to spinlocks will even speedup this case.

__inet_lookup_established() is pretty fast now we dont have to
dirty a contended cache line (read_lock/read_unlock)

Only established and timewait hashtable are converted to RCU
(bind table and listen table are still using traditional locking)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2008-11-16 19:40:17 -08:00
committed by David S. Miller
parent 88ab1932ea
commit 3ab5aee7fe
13 changed files with 152 additions and 85 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
net/ipv4/inet_diag.c
View File

@@ -778,18 +778,19 @@ skip_listen_ht:
struct inet_ehash_bucket *head = &hashinfo->ehash[i];
rwlock_t *lock = inet_ehash_lockp(hashinfo, i);
struct sock *sk;
struct hlist_node *node;
struct hlist_nulls_node *node;
num = 0;
if (hlist_empty(&head->chain) && hlist_empty(&head->twchain))
if (hlist_nulls_empty(&head->chain) &&
hlist_nulls_empty(&head->twchain))
continue;
if (i > s_i)
s_num = 0;
read_lock_bh(lock);
sk_for_each(sk, node, &head->chain) {
sk_nulls_for_each(sk, node, &head->chain) {
struct inet_sock *inet = inet_sk(sk);
if (num < s_num)