Re: Spin Lock sleep resolution

On Tue, 18 Jun 2013 11:41:06 +0300
Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> wrote:

> Oh, interesting. What kind of hardware are you running on? To be honest,
> I'm not sure what my test hardware is, it's managed by another team
> across the world, but /proc/cpuinfo says:
>
> model name : Intel(R) Xeon(R) CPU E5-4640 0 @ 2.40GHz

It claims to have 80 of these:

model name : Intel(R) Xeon(R) CPU E7-L8867 @2.13GHz

Postgres is on ramfs on these with unlogged tables.

> And it's running in a virtual machine on VMware; that might also be a
> factor.

I'm not a fan of virtualization. It makes performance even harder to
reason about.

> It would be good to test the TAS_SPIN nonlocked patch on a variety of
> systems. The comments in s_lock.h say that on Opteron, the non-locked
> test is a huge loss. In particular, would be good to re-test that on a
> modern AMD system.

I'll see what I can do. However I don't have acces to any large modern AMD
systems.

-dg

--
David Gould 510 282 0869 daveg(at)sonic(dot)net
If simplicity worked, the world would be overrun with insects.