lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[NET]: move struct proto_ops to const

Browse Source 
I noticed that some of 'struct proto_ops' used in the kernel may share
a cache line used by locks or other heavily modified data. (default
linker alignement is 32 bytes, and L1_CACHE_LINE is 64 or 128 at
least)

This patch makes sure a 'struct proto_ops' can be declared as const,
so that all cpus can share all parts of it without false sharing.

This is not mandatory : a driver can still use a read/write structure
if it needs to (and eventually a __read_mostly)

I made a global stubstitute to change all existing occurences to make
them const.

This should reduce the possibility of false sharing on SMP, and
speedup some socket system calls.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2005-12-22 12:49:22 -08:00
committed by David S. Miller
parent 77d76ea310
commit 90ddc4f047
33 changed files with 66 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
net/bluetooth/sco.c
View File

@ -56,7 +56,7 @@
#define VERSION "0.5"
static struct proto_ops sco_sock_ops;
static const struct proto_ops sco_sock_ops;
static struct bt_sock_list sco_sk_list = {
.lock = RW_LOCK_UNLOCKED
@ -914,7 +914,7 @@ static ssize_t sco_sysfs_show(struct class *dev, char *buf)
static CLASS_ATTR(sco, S_IRUGO, sco_sysfs_show, NULL);
static struct proto_ops sco_sock_ops = {
static const struct proto_ops sco_sock_ops = {
.family = PF_BLUETOOTH,
.owner = THIS_MODULE,
.release = sco_sock_release,