[SOCK]: Enumerate struct proto-s to facilitate percpu inuse accounting (v2).

The inuse counters are going to become a per-cpu array.  Introduce an
index for this array on the struct proto.

To handle the case of proto register-unregister-register loop the
bitmap is used. All its bits manipulations are protected with
proto_list_lock and a sanity check for the bitmap being exhausted is
also added.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pavel Emelyanov 2008-03-28 16:38:17 -07:00 committed by David S. Miller
parent bc578a54f0
commit 13ff3d6fa4
2 changed files with 35 additions and 0 deletions

View File

@ -562,6 +562,7 @@ struct proto {
/* Keeping track of sockets in use */
#ifdef CONFIG_PROC_FS
unsigned int inuse_idx;
struct pcounter inuse;
#endif

View File

@ -1940,6 +1940,38 @@ EXPORT_SYMBOL(sk_common_release);
static DEFINE_RWLOCK(proto_list_lock);
static LIST_HEAD(proto_list);
#ifdef CONFIG_PROC_FS
#define PROTO_INUSE_NR 64 /* should be enough for the first time */
static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
static void assign_proto_idx(struct proto *prot)
{
prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
return;
}
set_bit(prot->inuse_idx, proto_inuse_idx);
}
static void release_proto_idx(struct proto *prot)
{
if (prot->inuse_idx != PROTO_INUSE_NR - 1)
clear_bit(prot->inuse_idx, proto_inuse_idx);
}
#else
static inline void assign_proto_idx(struct proto *prot)
{
}
static inline void release_proto_idx(struct proto *prot)
{
}
#endif
int proto_register(struct proto *prot, int alloc_slab)
{
char *request_sock_slab_name = NULL;
@ -2000,6 +2032,7 @@ int proto_register(struct proto *prot, int alloc_slab)
write_lock(&proto_list_lock);
list_add(&prot->node, &proto_list);
assign_proto_idx(prot);
write_unlock(&proto_list_lock);
return 0;
@ -2026,6 +2059,7 @@ EXPORT_SYMBOL(proto_register);
void proto_unregister(struct proto *prot)
{
write_lock(&proto_list_lock);
release_proto_idx(prot);
list_del(&prot->node);
write_unlock(&proto_list_lock);