From 13ff3d6fa4e6d8b6ee7c64245a0078e6a0e6f977 Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@openvz.org>
Date: Fri, 28 Mar 2008 16:38:17 -0700
Subject: [PATCH] [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>
---
include/net/sock.h | 1 +
net/core/sock.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/net/sock.h b/include/net/sock.h
index 1c9d059223ee..abc6341f536f 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -562,6 +562,7 @@ struct proto {
/* Keeping track of sockets in use */
#ifdef CONFIG_PROC_FS
+ unsigned int inuse_idx;
struct pcounter inuse;
#endif
diff --git a/net/core/sock.c b/net/core/sock.c
index 3ee95060dbd0..7d2c8add5f5a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -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);
--
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