Re: OOM when adding ipv6 route: How to make available more per-cpumemory?
From: Ben Greear
Date: Fri Nov 05 2010 - 20:08:03 EST
On 11/05/2010 03:11 PM, Eric Dumazet wrote:
Le vendredi 05 novembre 2010 Ã 21:20 +0100, Eric Dumazet a Ãcrit :
Your vmalloc space is very fragmented. pcpu_get_vm_areas() want
hugepages (4MB on your machine, 2MB on mine because I have
CONFIG_HIGHMEM64G=y)
Well, this is wrong. We use normal (4KB) pages, unfortunately.
I have a NUMA machine, with two nodes, so pcpu_get_vm_areas() allocates
two zones, one for each node, with a 'known' offset between them.
Then, 4KB pages are allocated to populate the zone when needed.
# grep pcpu_get_vm_areas /proc/vmallocinfo
0xffffe8ffa0400000-0xffffe8ffa0600000 2097152 pcpu_get_vm_areas+0x0/0x740 vmalloc
0xffffe8ffffc00000-0xffffe8ffffe00000 2097152 pcpu_get_vm_areas+0x0/0x740 vmalloc
BTW, we dont have the number of pages currently allocated in each
'vmalloc' zone, and/or node information.
Tejun, do you have plans to use hugepages eventually ?
(and fallback to 4KB pages, but most percpu data are allocated right
after boot)
We just tried creating 1000 macvlans with IPv6 addrs on a 64-bit machine
with 12GB RAM. Only around 520 interfaces properly set their IPs, and
again there are errors about of-of-memory from 'ip', but no obvious
splats in dmesg.
'top' shows 10G or so free.
It will take some time to figure out what exactly is returning
the ENOMEM....
Thanks,
Ben
Thanks
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc http://www.candelatech.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/