Messages in this thread | | | Subject | Re: x86: 8K stacks by default | From | Andi Kleen <> | Date | Fri, 02 May 2008 11:05:16 +0200 |
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Ingo Molnar <mingo@elte.hu> writes: > > The plan is to remove "this overflows my stack here and now" technical > argument: we'll add the stack-footprint measurement tracing plugin from > -rt to ftrace and get that upstream. In -rt's tracer we can measure, > track and trace the exact worst-case stack footprint of a system, since > bootup. It relies on the function tracer which looks at the current > stack footprint at every given moment. It's not a statistical sample, it > tracks the true worst-case stack footprint.
I had such a measurement patch a long time ago for 2.4 x86-64 (ftp://ftp.x86-64.org/pub/linux-x86_64/debug/stackcheck-1)
But the problem today is the same as it was back then: you can't really get the production users with the nasty workloads who actually trigger the difficult overflows to run something like this which has quite high runtime overhead.
> _Then_ there can be no real technical argument about making the more > robust 4K stacks the default.
You typoed: s/more/less/
-Andi
P.S. I agree with Alan that the interrupt stacks should be always enabled even with 8k stacks.
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