linux-toradex.git/net/ipv4/fib_lookup.h, branch v3.10.70

ipv4: Fix nexthop caching wrt. scoping.

2011-03-25T01:06:47+00:00

Move the scope value out of the fib alias entries and into fib_info,
so that we always use the correct scope when recomputing the nexthop
cached source address.

Reported-by: Julian Anastasov 
Signed-off-by: David S. Miller

ipv4: Kill fib_semantic_match declaration from fib_lookup.h

2011-03-12T23:08:53+00:00

This function no longer exists.

Signed-off-by: David S. Miller

ipv4: Inline fib_semantic_match into check_leaf

2011-03-07T23:19:39+00:00

This elimiates a lot of pure overhead due to parameter
passing.

Signed-off-by: David S. Miller

ipv4: Remember FIB alias list head and table in lookup results.

2011-02-01T00:10:03+00:00

This will be used later to implement fib_select_default() in a
completely generic manner, instead of the current situation where the
default route is re-looked up in the TRIE/HASH table and then the
available aliases are analyzed.

Signed-off-by: David S. Miller

fib: fib_result_assign() should not change fib refcounts

2010-11-04T19:05:32+00:00

After commit ebc0ffae5 (RCU conversion of fib_lookup()),
fib_result_assign()  should not change fib refcounts anymore.

Thanks to Michael who did the bisection and bug report.

Reported-by: Michael Ellerman 
Tested-by: Michael Ellerman 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

fib: introduce fib_alias_accessed() helper

2010-10-21T10:09:41+00:00

Perf tools session at NFWS 2010 pointed out a false sharing on struct
fib_alias that can be avoided pretty easily, if we set FA_S_ACCESSED bit
only if needed (ie : not already set)

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

fib_hash: RCU conversion phase 2

2010-10-17T20:53:16+00:00

Get rid of fib_hash_lock rwlock.

The fn_zone hash table resize is the noticeable part of this patch.

I added a seqlock per fn_zone, so that readers can restart their lookup
in the (very rare) case a writer expanded the hash table.

Add rcu heads in fib_alias and fib_node, use call_rcu() to defer their
freeing, and use appropriate _rcu list manipulations.

Stress test (160.000.000 udp frames sent, IP route cache disabled to
mimic DDOS attack, FIB_HASH)

Before:
real	0m41.191s
user	0m13.137s
sys	8m55.241s

After:
real	0m38.091s
user	0m13.189s
sys	7m53.018s

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

fib: RCU conversion of fib_lookup()

2010-10-06T03:39:38+00:00

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 
Signed-off-by: David S. Miller

ipv4: cleanup - remove two unused parameters from fib_semantic_match().

2009-05-18T22:16:37+00:00

Signed-off-by: Rami Rosen 
Signed-off-by: David S. Miller

[IPV4] FIB_HASH: Reduce memory needs and speedup lookups

2008-01-28T23:02:46+00:00

Currently, sizeof(struct fib_alias) is 24 or 48 bytes on 32/64 bits
arches.

Because of SLAB_HWCACHE_ALIGN requirement, these are rounded to 32 and
64 bytes respectively.

This patch moves rcu to the end of fib_alias, and conditionally
defines it only for CONFIG_IP_FIB_TRIE.

We also remove SLAB_HWCACHE_ALIGN requirement for fib_alias and
fib_node objects because it is not necessary.

(BTW SLUB currently denies it for objects smaller than
cache_line_size() / 2, but not SLAB)

Finally, sizeof(fib_alias) go back to 16 and 32 bytes.

Then, we can embed one fib_alias on each fib_node, to favor locality.
Most of the time access to the fib_alias will be free because one
cache line contains both the list head (fn_alias) and (one of) the
list element.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller