Messages in this thread | | | Date | Sun, 20 Apr 2008 15:33:17 -0700 | From | Arjan van de Ven <> | Subject | Re: x86: 4kstacks default |
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On Sun, 20 Apr 2008 22:01:46 +0200 Andi Kleen <andi@firstfloor.org> wrote:
> > > > These are real customer workloads; java based "many things going > > on" at a time showed several thousands of threads fin the system (a > > dozen or two per request, multiplied by the number of outstanding > > connections) for *real customers*. > > Several thousands or 50k? Several thousands sounds large, but not > entirely unreasonable, but it is far from 50k.
it is you who keeps putting up the 50k argument. What I'm talking about is in the 10k to 20k range; and that is actual workloads by real customers. > > > That you don't take that serious, fair, you can take serious > > whatever you want. > > No I don't take 50k threads on 32bit serious. And I hope you do not > either.
[ removed a bunch of stuff about 50k again ]
> > > was the observation that fragmentation is fundamentally unsolvable. > > Where was that observation?
it was in the commit message from me you quoted, and was rather widely discussed at the time. It's also basic math; the Linux VM gets to deal with both short and long lasting allocations; no matter how hard you try to get some degree of fragmentation; especially due to the 15:1 acceleration you get due to the lowmem issue.
And before you say "you should use 64 bit on such machines"; I would love it if more people used 64 bit linux. Sadly the adoption rate of that is not very good still.... by far ;(
> > > Yes 2.4 sucked a lot more than 2.6 does. But even 2.6 will (and > > does) have fragmentation issues. We don't have effective physical > > address based reclaim yet for higher order allocs. > > I don't see any evidence that there are serious order 1 fragmentation > issues on 2.6.
I assume you're not asking me to give you customer confidential data from a previous job in public ;)
>If you have any please post it.
just like you're posting the evidence that 4k stacks overflows?
Google scores:
1-order allocation failed 54000 pages do_IRQ: stack overflow 4560 pages
-- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org
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