Andrew Morton wrote:
On Fri, 02 Mar 2007 16:19:19 -0500
Rik van Riel <[EMAIL PROTECTED]> wrote:
Bill Irwin wrote:
On Fri, Mar 02, 2007 at 01:23:28PM -0500, Rik van Riel wrote:
With 32 CPUs diving into the page reclaim simultaneously,
each trying to scan a fraction of memory, this is disastrous
for performance. A 256GB system should be even worse.
Thundering herds of a sort pounding the LRU locks from direct reclaim
have set off the NMI oopser for users here.
Ditto here.
Opterons?
It's happened on IA64, too. Probably on Intel x86-64 as well.
The main reason they end up pounding the LRU locks is the
swappiness heuristic. They scan too much before deciding
that it would be a good idea to actually swap something
out, and with 32 CPUs doing such scanning simultaneously...
What kernel version?
Customers are on the 2.6.9 based RHEL4 kernel, but I believe
we have reproduced the problem on 2.6.18 too during stress
tests.
I have no reason to believe we should stick our heads in the
sand and pretend it no longer exists on 2.6.21.
--
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is. Each group
calls the other unpatriotic.
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