Messages in this thread | | | Date | Wed, 16 Apr 2008 14:47:28 +0200 | From | Ingo Molnar <> | Subject | Re: Does process need to have a kernel-side stack all the time? |
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* Andi Kleen <andi@firstfloor.org> wrote:
> Denys Vlasenko <vda.linux@googlemail.com> writes: > > > A lot of effort went into minimizing of stack usage. > > If I understand it correctly, one of the reasons for this > > was to be efficient and not have lots of pages > > used for stacks when we have a lot of threads > > (tens of thousands). > > Actually the real reason the 4K stacks were introduced IIRC was that > the VM is not very good at allocation of order > 0 pages and that only > using order 0 and not order 1 in normal operation prevented some > stalls.
no, the primary motivation Arjan and me started working on 4K stacks and implemented it was what Denys mentioned: i had a testcase that ran 50,000 threads before it ran out of memory - i wanted it to run 100,000 threads. The improved order-0 behavior was just icing on the cake.
Ingo
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