[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4A513D0D.5070204@itcare.pl>
Date: Mon, 06 Jul 2009 01:53:49 +0200
From: Paweł Staszewski <pstaszewski@...are.pl>
To: Jarek Poplawski <jarkao2@...il.com>
CC: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Linux Network Development list <netdev@...r.kernel.org>,
Robert Olsson <robert@...ur.slu.se>
Subject: Re: [PATCH net-2.6] Re: rib_trie / Fix inflate_threshold_root. Now=15
size=11 bits
kernel 2.6.29.5 preempt
bgp starts normal and kernel know routes normaly like without patch
Here are some fib_triestats
cat /proc/net/fib_triestat
Basic info: size of leaf: 20 bytes, size of tnode: 36 bytes.
Main:
Aver depth: 2.44
Max depth: 6
Leaves: 277888
Prefixes: 291399
Internal nodes: 66818
1: 33080 2: 14584 3: 10788 4: 4911 5: 2185 6: 900 7:
366 8: 3 17: 1
Pointers: 595584
Null ptrs: 250879
Total size: 18072 kB
Counters:
---------
gets = 1052940
backtracks = 55985
semantic match passed = 1034114
semantic match miss = 5
null node hit= 534415
skipped node resize = 0
Local:
Aver depth: 3.75
Max depth: 5
Leaves: 12
Prefixes: 13
Internal nodes: 10
1: 9 2: 1
Pointers: 22
Null ptrs: 1
Total size: 2 kB
Counters:
---------
gets = 1057636
backtracks = 1101307
semantic match passed = 4751
semantic match miss = 0
null node hit= 195605
skipped node resize = 0
kernel 2.6.29.5 no-preempt
All is ok like with preempt kernel (andl all working in normal time
"routes propagation")
cat /sys/module/fib_trie/parameters/sync_pages
1000
cat /proc/net/fib_triestat
Basic info: size of leaf: 20 bytes, size of tnode: 36 bytes.
Main:
Aver depth: 2.45
Max depth: 6
Leaves: 277905
Prefixes: 291416
Internal nodes: 66863
1: 33119 2: 14594 3: 10782 4: 4911 5: 2187 6: 901 7:
365 8: 3 17: 1
Pointers: 595654
Null ptrs: 250887
Total size: 18074 kB
Counters:
---------
gets = 1060650
backtracks = 53161
semantic match passed = 1041008
semantic match miss = 12
null node hit= 504478
skipped node resize = 0
Local:
Aver depth: 3.75
Max depth: 5
Leaves: 12
Prefixes: 13
Internal nodes: 10
1: 9 2: 1
Pointers: 22
Null ptrs: 1
Total size: 2 kB
Counters:
---------
gets = 1065517
backtracks = 1095422
semantic match passed = 4954
semantic match miss = 0
null node hit= 195584
skipped node resize = 0
So i make tests with changing sync_pages
And
####################################
sync_pages: 64
total size reach maximum in 17sec
Basic info: size of leaf: 20 bytes, size of tnode: 36 bytes.
Main:
Aver depth: 2.43
Max depth: 6
Leaves: 271928
Prefixes: 285435
Internal nodes: 66185
1: 32904 2: 14554 3: 10740 4: 4677 5: 2047 6: 901 7:
361 17: 1
Pointers: 585224
Null ptrs: 247112
Total size: 17729 kB
Counters:
---------
gets = 5313544
backtracks = 230501
semantic match passed = 5233998
semantic match miss = 61
null node hit= 2757531
skipped node resize = 0
Local:
Aver depth: 3.75
Max depth: 5
Leaves: 12
Prefixes: 13
Internal nodes: 10
1: 9 2: 1
Pointers: 22
Null ptrs: 1
Total size: 2 kB
Counters:
---------
gets = 5332471
backtracks = 4708505
semantic match passed = 19264
semantic match miss = 0
null node hit= 782757
skipped node resize = 0
######################################
sync_pages: 128
Fib trie Total size reach max in 14sec
Basic info: size of leaf: 20 bytes, size of tnode: 36 bytes.
Main:
Aver depth: 2.44
Max depth: 6
Leaves: 277915
Prefixes: 291427
Internal nodes: 66832
1: 33085 2: 14597 3: 10785 4: 4908 5: 2187 6: 900 7:
366 8: 3 17: 1
Pointers: 595638
Null ptrs: 250892
Total size: 18074 kB
Counters:
---------
gets = 6698058
backtracks = 307491
semantic match passed = 6593421
semantic match miss = 66
null node hit= 3498560
skipped node resize = 0
Local:
Aver depth: 3.75
Max depth: 5
Leaves: 12
Prefixes: 13
Internal nodes: 10
1: 9 2: 1
Pointers: 22
Null ptrs: 1
Total size: 2 kB
Counters:
---------
gets = 6721120
backtracks = 5934017
semantic match passed = 23440
semantic match miss = 0
null node hit= 978008
skipped node resize = 0
#########################################
sync_pages: 256
hmm no difference also in 10sec
Basic info: size of leaf: 20 bytes, size of tnode: 36 bytes.
Main:
Aver depth: 2.44
Max depth: 6
Leaves: 277913
Prefixes: 291425
Internal nodes: 66829
1: 33082 2: 14596 3: 10786 4: 4909 5: 2186 6: 900 7:
366 8: 3 17: 1
Pointers: 595620
Null ptrs: 250879
Total size: 18073 kB
Counters:
---------
gets = 4637474
backtracks = 188624
semantic match passed = 4577266
semantic match miss = 61
null node hit= 2451890
skipped node resize = 0
Local:
Aver depth: 3.75
Max depth: 5
Leaves: 12
Prefixes: 13
Internal nodes: 10
1: 9 2: 1
Pointers: 22
Null ptrs: 1
Total size: 2 kB
Counters:
---------
gets = 4651791
backtracks = 3716400
semantic match passed = 14613
semantic match miss = 0
null node hit= 587208
skipped node resize = 0
And with sync_pages higher that 256 time of filling kernel routes is the
same approx 10sec.
I make this test bu use:
watch -n1 cat /proc/net/fib_triestat
timer start when Total size was 1kB and stop when Total size reach 18073 kB
Regards
Paweł Staszewski
Jarek Poplawski pisze:
> On Sun, Jul 05, 2009 at 02:32:32PM -0700, Paul E. McKenney wrote:
>
>> On Sun, Jul 05, 2009 at 07:32:08PM +0200, Jarek Poplawski wrote:
>>
>>> On Sun, Jul 05, 2009 at 06:20:03PM +0200, Jarek Poplawski wrote:
>>>
>>>> On Sun, Jul 05, 2009 at 02:30:03AM +0200, Paweł Staszewski wrote:
>>>>
>>>>> Oh
>>>>>
>>>>> I forgot - please Jarek give me patch with sync rcu and i will make test
>>>>> on preempt kernel
>>>>>
>>>> Probably non-preempt kernel might need something like this more, but
>>>> comparing is always interesting. This patch is based on Paul's
>>>> suggestion (I hope).
>>>>
>>> Hold on ;-) Here is something even better... Syncing after 128 pages
>>> might be still too slow, so here is a higher initial value, 1000, plus
>>> you can change this while testing in:
>>>
>>> /sys/module/fib_trie/parameters/sync_pages
>>>
>>> It would be interesting to find the lowest acceptable value.
>>>
>> Looks like a promising approach to me!
>>
>> Thanx, Paul
>>
>
> Hmm... As a matter of fact, I'm a bit sceptical now: I'm worrying this
> synchronize_rcu done at the lowest acceptable rate could be actually
> mostly idle or on the contrary too late. Probably some more complex
> (per cpu?) accounting would be necessary to really matter here, but
> on the other hand these problems weren't reported often enough.
>
> Thanks,
> Jarek P.
>
>
>>> ---> (synchronize take 8; apply on top of the 2.6.29.x with the last
>>> all-in-one patch, or net-2.6)
>>>
>>> net/ipv4/fib_trie.c | 12 ++++++++++++
>>> 1 files changed, 12 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
>>> index 00a54b2..decc8d0 100644
>>> --- a/net/ipv4/fib_trie.c
>>> +++ b/net/ipv4/fib_trie.c
>>> @@ -71,6 +71,7 @@
>>> #include <linux/netlink.h>
>>> #include <linux/init.h>
>>> #include <linux/list.h>
>>> +#include <linux/moduleparam.h>
>>> #include <net/net_namespace.h>
>>> #include <net/ip.h>
>>> #include <net/protocol.h>
>>> @@ -164,6 +165,10 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn);
>>> static struct tnode *halve(struct trie *t, struct tnode *tn);
>>> /* tnodes to free after resize(); protected by RTNL */
>>> static struct tnode *tnode_free_head;
>>> +static size_t tnode_free_size;
>>> +
>>> +static int sync_pages __read_mostly = 1000;
>>> +module_param(sync_pages, int, 0640);
>>>
>>> static struct kmem_cache *fn_alias_kmem __read_mostly;
>>> static struct kmem_cache *trie_leaf_kmem __read_mostly;
>>> @@ -393,6 +398,8 @@ static void tnode_free_safe(struct tnode *tn)
>>> BUG_ON(IS_LEAF(tn));
>>> tn->tnode_free = tnode_free_head;
>>> tnode_free_head = tn;
>>> + tnode_free_size += sizeof(struct tnode) +
>>> + (sizeof(struct node *) << tn->bits);
>>> }
>>>
>>> static void tnode_free_flush(void)
>>> @@ -404,6 +411,11 @@ static void tnode_free_flush(void)
>>> tn->tnode_free = NULL;
>>> tnode_free(tn);
>>> }
>>> +
>>> + if (tnode_free_size >= PAGE_SIZE * sync_pages) {
>>> + tnode_free_size = 0;
>>> + synchronize_rcu();
>>> + }
>>> }
>>>
>>> static struct leaf *leaf_new(void)
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>>> the body of a message to majordomo@...r.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists