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author | Pavel Emelyanov <xemul@openvz.org> | 2008-03-28 16:38:43 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2008-03-28 16:38:43 -0700 |
commit | 1338d466d9c3f8a65cc6d83c629cd906f2a989f8 (patch) | |
tree | 2f30913c1c9c6d3c0616ac593e79b0431cc150d3 /net/core/sock.c | |
parent | 13ff3d6fa4e6d8b6ee7c64245a0078e6a0e6f977 (diff) | |
download | linux-1338d466d9c3f8a65cc6d83c629cd906f2a989f8.tar.gz linux-1338d466d9c3f8a65cc6d83c629cd906f2a989f8.tar.bz2 linux-1338d466d9c3f8a65cc6d83c629cd906f2a989f8.zip |
[SOCK]: Introduce a percpu inuse counters array (v2).
And redirect sock_prot_inuse_add and _get to use one.
As far as the dereferences are concerned. Before the patch we made
1 dereference to proto->inuse.add call, the call itself and then
called the __get_cpu_var() on a static variable. After the patch we
make a direct call, then one dereference to proto->inuse_idx and
then the same __get_cpu_var() on a still static variable. So this
patch doesn't seem to produce performance penalty on SMP.
This is not per-net yet, but I will deliberately make NET_NS=y case
separated from NET_NS=n one, since it'll cost us one-or-two more
dereferences to get the struct net and the inuse counter.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sock.c')
-rw-r--r-- | net/core/sock.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 7d2c8add5f5a..174c64bc7a43 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1942,8 +1942,30 @@ static LIST_HEAD(proto_list); #ifdef CONFIG_PROC_FS #define PROTO_INUSE_NR 64 /* should be enough for the first time */ +struct prot_inuse { + int val[PROTO_INUSE_NR]; +}; static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR); +static DEFINE_PER_CPU(struct prot_inuse, prot_inuse); + +void sock_prot_inuse_add(struct proto *prot, int val) +{ + __get_cpu_var(prot_inuse).val[prot->inuse_idx] += val; +} +EXPORT_SYMBOL_GPL(sock_prot_inuse_add); + +int sock_prot_inuse_get(struct proto *prot) +{ + int cpu, idx = prot->inuse_idx; + int res = 0; + + for_each_possible_cpu(cpu) + res += per_cpu(prot_inuse, cpu).val[idx]; + + return res >= 0 ? res : 0; +} +EXPORT_SYMBOL_GPL(sock_prot_inuse_get); static void assign_proto_idx(struct proto *prot) { |