From 832b4c5e184391773e462653aa862a8cab71f38d Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 29 Aug 2006 16:48:09 -0700 Subject: [PATCH] [IPV4] fib: convert reader/writer to spinlock Ther is no point in using a more expensive reader/writer lock for a low contention lock like the fib_info_lock. The only reader case is in handling route redirects. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv4/fib_semantics.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 51738000f3d..38bca473c7e 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -49,7 +49,7 @@ #define FSprintk(a...) -static DEFINE_RWLOCK(fib_info_lock); +static DEFINE_SPINLOCK(fib_info_lock); static struct hlist_head *fib_info_hash; static struct hlist_head *fib_info_laddrhash; static unsigned int fib_hash_size; @@ -159,7 +159,7 @@ void free_fib_info(struct fib_info *fi) void fib_release_info(struct fib_info *fi) { - write_lock_bh(&fib_info_lock); + spin_lock_bh(&fib_info_lock); if (fi && --fi->fib_treeref == 0) { hlist_del(&fi->fib_hash); if (fi->fib_prefsrc) @@ -172,7 +172,7 @@ void fib_release_info(struct fib_info *fi) fi->fib_dead = 1; fib_info_put(fi); } - write_unlock_bh(&fib_info_lock); + spin_unlock_bh(&fib_info_lock); } static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) @@ -254,7 +254,7 @@ int ip_fib_check_default(u32 gw, struct net_device *dev) struct fib_nh *nh; unsigned int hash; - read_lock(&fib_info_lock); + spin_lock(&fib_info_lock); hash = fib_devindex_hashfn(dev->ifindex); head = &fib_info_devhash[hash]; @@ -262,12 +262,12 @@ int ip_fib_check_default(u32 gw, struct net_device *dev) if (nh->nh_dev == dev && nh->nh_gw == gw && !(nh->nh_flags&RTNH_F_DEAD)) { - read_unlock(&fib_info_lock); + spin_unlock(&fib_info_lock); return 0; } } - read_unlock(&fib_info_lock); + spin_unlock(&fib_info_lock); return -1; } @@ -598,7 +598,7 @@ static void fib_hash_move(struct hlist_head *new_info_hash, unsigned int old_size = fib_hash_size; unsigned int i, bytes; - write_lock_bh(&fib_info_lock); + spin_lock_bh(&fib_info_lock); old_info_hash = fib_info_hash; old_laddrhash = fib_info_laddrhash; fib_hash_size = new_size; @@ -639,7 +639,7 @@ static void fib_hash_move(struct hlist_head *new_info_hash, } fib_info_laddrhash = new_laddrhash; - write_unlock_bh(&fib_info_lock); + spin_unlock_bh(&fib_info_lock); bytes = old_size * sizeof(struct hlist_head *); fib_hash_free(old_info_hash, bytes); @@ -820,7 +820,7 @@ link_it: fi->fib_treeref++; atomic_inc(&fi->fib_clntref); - write_lock_bh(&fib_info_lock); + spin_lock_bh(&fib_info_lock); hlist_add_head(&fi->fib_hash, &fib_info_hash[fib_info_hashfn(fi)]); if (fi->fib_prefsrc) { @@ -839,7 +839,7 @@ link_it: head = &fib_info_devhash[hash]; hlist_add_head(&nh->nh_hash, head); } endfor_nexthops(fi) - write_unlock_bh(&fib_info_lock); + spin_unlock_bh(&fib_info_lock); return fi; err_inval: -- 2.39.2