lkml.org 
[lkml]   [2010]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: OOM when adding ipv6 route: How to make available more per-cpu memory?
From
Date
Le vendredi 05 novembre 2010 à 17:07 -0700, Ben Greear a écrit :

> 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....

At least, nothing to do with percpu stuff ?

On my 4GB machine, 16 'cpus' (but 32 possible cpus), I was able to
allocate.
8192 percpu 8192 bytes structures

(total : 32 * 8192 * 8192 = 2 Gbytes)

setup_percpu: NR_CPUS:32 nr_cpumask_bits:32 nr_cpu_ids:32 nr_node_ids:2
PERCPU: Embedded 26 pages/cpu @ffff88007fc00000 s76032 r8192 d22272 u131072
pcpu-alloc: s76032 r8192 d22272 u131072 alloc=1*2097152
pcpu-alloc: [0] 00 02 04 06 08 10 12 14 17 19 21 23 25 27 29 31
pcpu-alloc: [1] 01 03 05 07 09 11 13 15 16 18 20 22 24 26 28 30

grep Vmalloc /proc/meminfo
VmallocTotal: 34359738367 kB
VmallocUsed: 2202592 kB
VmallocChunk: 34356996456 kB

Make sure udev / hotplug is not the problem, if you create your devices
very fast.

(modprobe dummy numdummies=2000) can be very slow because of that.
All tasks are fighting for RTNL or sysfs mutex.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-11-06 08:29    [W:0.072 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site