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authorEric Dumazet <eric.dumazet@gmail.com>2010-10-05 14:41:36 +0400
committerDavid S. Miller <davem@davemloft.net>2010-10-06 07:39:38 +0400
commitebc0ffae5dfb4447e0a431ffe7fe1d467c48bbb9 (patch)
tree395e50547ffccc6b73e04a44190eb4b4f2d2316b /net/ipv4/fib_frontend.c
parentc2952c314b4fe61820ba8fd6c949eed636140d52 (diff)
downloadlinux-ebc0ffae5dfb4447e0a431ffe7fe1d467c48bbb9.tar.xz
fib: RCU conversion of fib_lookup()
fib_lookup() converted to be called in RCU protected context, no reference taken and released on a contended cache line (fib_clntref) fib_table_lookup() and fib_semantic_match() get an additional parameter. struct fib_info gets an rcu_head field, and is freed after an rcu grace period. Stress test : (Sending 160.000.000 UDP frames on same neighbour, IP route cache disabled, dual E5540 @2.53GHz, 32bit kernel, FIB_HASH) (about same results for FIB_TRIE) Before patch : real 1m31.199s user 0m13.761s sys 23m24.780s After patch: real 1m5.375s user 0m14.997s sys 15m50.115s Before patch Profile : 13044.00 15.4% __ip_route_output_key vmlinux 8438.00 10.0% dst_destroy vmlinux 5983.00 7.1% fib_semantic_match vmlinux 5410.00 6.4% fib_rules_lookup vmlinux 4803.00 5.7% neigh_lookup vmlinux 4420.00 5.2% _raw_spin_lock vmlinux 3883.00 4.6% rt_set_nexthop vmlinux 3261.00 3.9% _raw_read_lock vmlinux 2794.00 3.3% fib_table_lookup vmlinux 2374.00 2.8% neigh_resolve_output vmlinux 2153.00 2.5% dst_alloc vmlinux 1502.00 1.8% _raw_read_lock_bh vmlinux 1484.00 1.8% kmem_cache_alloc vmlinux 1407.00 1.7% eth_header vmlinux 1406.00 1.7% ipv4_dst_destroy vmlinux 1298.00 1.5% __copy_from_user_ll vmlinux 1174.00 1.4% dev_queue_xmit vmlinux 1000.00 1.2% ip_output vmlinux After patch Profile : 13712.00 15.8% dst_destroy vmlinux 8548.00 9.9% __ip_route_output_key vmlinux 7017.00 8.1% neigh_lookup vmlinux 4554.00 5.3% fib_semantic_match vmlinux 4067.00 4.7% _raw_read_lock vmlinux 3491.00 4.0% dst_alloc vmlinux 3186.00 3.7% neigh_resolve_output vmlinux 3103.00 3.6% fib_table_lookup vmlinux 2098.00 2.4% _raw_read_lock_bh vmlinux 2081.00 2.4% kmem_cache_alloc vmlinux 2013.00 2.3% _raw_spin_lock vmlinux 1763.00 2.0% __copy_from_user_ll vmlinux 1763.00 2.0% ip_output vmlinux 1761.00 2.0% ipv4_dst_destroy vmlinux 1631.00 1.9% eth_header vmlinux 1440.00 1.7% _raw_read_unlock_bh vmlinux Reference results, if IP route cache is enabled : real 0m29.718s user 0m10.845s sys 7m37.341s 25213.00 29.5% __ip_route_output_key vmlinux 9011.00 10.5% dst_release vmlinux 4817.00 5.6% ip_push_pending_frames vmlinux 4232.00 5.0% ip_finish_output vmlinux 3940.00 4.6% udp_sendmsg vmlinux 3730.00 4.4% __copy_from_user_ll vmlinux 3716.00 4.4% ip_route_output_flow vmlinux 2451.00 2.9% __xfrm_lookup vmlinux 2221.00 2.6% ip_append_data vmlinux 1718.00 2.0% _raw_spin_lock_bh vmlinux 1655.00 1.9% __alloc_skb vmlinux 1572.00 1.8% sock_wfree vmlinux 1345.00 1.6% kfree vmlinux Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_frontend.c')
-rw-r--r--net/ipv4/fib_frontend.c27
1 files changed, 13 insertions, 14 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index b05c23b05a9f..919f2ad19b49 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -168,8 +168,11 @@ struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
struct fib_result res = { 0 };
struct net_device *dev = NULL;
- if (fib_lookup(net, &fl, &res))
+ rcu_read_lock();
+ if (fib_lookup(net, &fl, &res)) {
+ rcu_read_unlock();
return NULL;
+ }
if (res.type != RTN_LOCAL)
goto out;
dev = FIB_RES_DEV(res);
@@ -177,7 +180,7 @@ struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
if (dev && devref)
dev_hold(dev);
out:
- fib_res_put(&res);
+ rcu_read_unlock();
return dev;
}
EXPORT_SYMBOL(__ip_dev_find);
@@ -207,11 +210,12 @@ static inline unsigned __inet_dev_addr_type(struct net *net,
local_table = fib_get_table(net, RT_TABLE_LOCAL);
if (local_table) {
ret = RTN_UNICAST;
- if (!fib_table_lookup(local_table, &fl, &res)) {
+ rcu_read_lock();
+ if (!fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) {
if (!dev || dev == res.fi->fib_dev)
ret = res.type;
- fib_res_put(&res);
}
+ rcu_read_unlock();
}
return ret;
}
@@ -235,6 +239,7 @@ EXPORT_SYMBOL(inet_dev_addr_type);
* - figure out what "logical" interface this packet arrived
* and calculate "specific destination" address.
* - check, that packet arrived from expected physical interface.
+ * called with rcu_read_lock()
*/
int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
struct net_device *dev, __be32 *spec_dst,
@@ -259,7 +264,6 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
struct net *net;
no_addr = rpf = accept_local = 0;
- rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (in_dev) {
no_addr = in_dev->ifa_list == NULL;
@@ -268,7 +272,6 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
if (mark && !IN_DEV_SRC_VMARK(in_dev))
fl.mark = 0;
}
- rcu_read_unlock();
if (in_dev == NULL)
goto e_inval;
@@ -278,7 +281,7 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
goto last_resort;
if (res.type != RTN_UNICAST) {
if (res.type != RTN_LOCAL || !accept_local)
- goto e_inval_res;
+ goto e_inval;
}
*spec_dst = FIB_RES_PREFSRC(res);
fib_combine_itag(itag, &res);
@@ -299,10 +302,8 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
#endif
if (dev_match) {
ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
- fib_res_put(&res);
return ret;
}
- fib_res_put(&res);
if (no_addr)
goto last_resort;
if (rpf == 1)
@@ -315,7 +316,6 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
*spec_dst = FIB_RES_PREFSRC(res);
ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
}
- fib_res_put(&res);
}
return ret;
@@ -326,8 +326,6 @@ last_resort:
*itag = 0;
return 0;
-e_inval_res:
- fib_res_put(&res);
e_inval:
return -EINVAL;
e_rpf:
@@ -873,15 +871,16 @@ static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
local_bh_disable();
frn->tb_id = tb->tb_id;
- frn->err = fib_table_lookup(tb, &fl, &res);
+ rcu_read_lock();
+ frn->err = fib_table_lookup(tb, &fl, &res, FIB_LOOKUP_NOREF);
if (!frn->err) {
frn->prefixlen = res.prefixlen;
frn->nh_sel = res.nh_sel;
frn->type = res.type;
frn->scope = res.scope;
- fib_res_put(&res);
}
+ rcu_read_unlock();
local_bh_enable();
}
}