Paweł Staszewski a écrit :

Hello ALL

Some time ago i report this:
http://bugzilla.kernel.org/show_bug.cgi?id=6648

and now with 2.6.29 / 2.6.29.1 / 2.6.29.3 and 2.6.30 it back
dmesg output:
oprofile: using NMI interrupt.
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits
Fix inflate_threshold_root. Now=15 size=11 bits

Curious, you seem to hit an old alloc_pages limit()... (MAX_ORDER allocation)

Your root node has 2^18 = 262144 pointers of 8 bytes -> 2097152 bytes (+ header -> 4194304 bytes)

But since following commit, we should use vmalloc() so this PAGE_SIZE<<10) limit
should not anymore be applied.

Could you do a "cat /proc/vmallocinfo" just to check your big tnodes are vmalloced() ?


commit 15be75cdb5db442d0e33d37b20832b88f3ccd383
Author: Stephen Hemminger [off-list ref]
Date:   Thu Apr 10 02:56:38 2008 -0700

    IPV4: fib_trie use vmalloc for large tnodes

    Use vmalloc rather than alloc_pages to avoid wasting memory.
    The problem is that tnode structure has a power of 2 sized array,
    plus a header. So the current code wastes almost half the memory
    allocated because it always needs the next bigger size to hold
    that small header.

    This is similar to an earlier patch by Eric, but instead of a list
    and lock, I used a workqueue to handle the fact that vfree can't
    be done in interrupt context.

    Signed-off-by: Stephen Hemminger [off-list ref]
    Signed-off-by: David S. Miller [off-list ref]

cat /proc/net/fib_triestat
Basic info: size of leaf: 40 bytes, size of tnode: 56 bytes.
Main:
       Aver depth:     2.28
       Max depth:      6
       Leaves:         276539
       Prefixes:       289922
       Internal nodes: 66762
         1: 35046  2: 13824  3: 9508  4: 4897  5: 2331  6: 1149  7: 5 
9: 1  18: 1
       Pointers: 691228
Null ptrs: 347928
Total size: 35709  kB

Counters:
---------
gets = 26276593
backtracks = 547306
semantic match passed = 26188746
semantic match miss = 1117
null node hit= 27285055
skipped node resize = 0

Local:
       Aver depth:     3.33
       Max depth:      4
       Leaves:         9
       Prefixes:       10
       Internal nodes: 8
         1: 8
       Pointers: 16
Null ptrs: 0
Total size: 2  kB

Counters:
---------
gets = 26642350
backtracks = 1282818
semantic match passed = 18166
semantic match miss = 0
null node hit= 0
skipped node resize = 0



This machine is running bgpd with two bgp peers / full route table

cat /proc/meminfo
MemTotal:       12279032 kB
MemFree:        11521920 kB
Buffers:           80288 kB
Cached:            34416 kB
SwapCached:            0 kB
Active:           286816 kB
Inactive:          82024 kB
Active(anon):     254296 kB
Inactive(anon):        0 kB
Active(file):      32520 kB
Inactive(file):    82024 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:        987988 kB
SwapFree:         987988 kB
Dirty:              1140 kB
Writeback:             0 kB
AnonPages:        254164 kB
Mapped:             5440 kB
Slab:             365084 kB
SReclaimable:      28784 kB
SUnreclaim:       336300 kB
PageTables:         2104 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     7127504 kB
Committed_AS:     267704 kB
VmallocTotal:   34359738367 kB
VmallocUsed:       11824 kB
VmallocChunk:   34359707815 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:        3392 kB
DirectMap2M:    12578816 kB


Interfaces mtu is1500