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Commit 13ff3d6f authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by David S. Miller
Browse files

[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: default avatarPavel Emelyanov <xemul@openvz.org>
Acked-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bc578a54

include/net/sock.h

+1 −0
Original line number Diff line number Diff line
@@ -562,6 +562,7 @@ struct proto { 


	/* Keeping track of sockets in use */

#ifdef CONFIG_PROC_FS

	unsigned int		inuse_idx;

	struct pcounter		inuse;

#endif

net/core/sock.c

+34 −0
Original line number Diff line number Diff line
@@ -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);