Re: huge tlb support

On Tue, Aug 21, 2012 at 11:31 AM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On Tuesday, August 21, 2012 05:30:28 PM Robert Haas wrote:
>> On Thu, Aug 16, 2012 at 10:53 PM, David Gould <daveg(at)sonic(dot)net> wrote:
>> > A warning, on RHEL 6.1 (2.6.32-131.4.1.el6.x86_64 #1 SMP) we have had
>> > horrible problems caused by transparent_hugepages running postgres on
>> > largish systems (128GB to 512GB memory, 32 cores). The system sometimes
>> > goes 99% system time and is very slow and unresponsive to the point of
>> > not successfully completing new tcp connections. Turning off
>> > transparent_hugepages fixes it.
>>
>> Yikes! Any idea WHY that happens?
>>
>> I'm inclined to think this torpedos any idea we might have of enabling
>> hugepages automatically whenever possible. I think we should just add
>> a GUC for this and call it good. If the state of the world improves
>> sufficiently in the future, we can adjust, but I think for right now
>> we should just do this in the simplest way possible and move on.
> He is talking about transparent hugepages not hugepages afaics.

Hmm. I guess you're right. But why would it be different?

--
Robert Haas
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