Re: [2.6 patch] i386: always use 4k stacks

From: Oliver Neukum
Date: Wed Nov 16 2005 - 03:34:07 EST

Am Mittwoch, 16. November 2005 09:03 schrieb Arjan van de Ven:
> * less CPU cache footprint due to interrupt stacks
> Â Â- interrupt stacks are per cpu now instead of borrowing the per
> Â Â Âthread stack space; this both has less impact on the caches, and
> Â Â Âhas more cache hits; the per cpu stack will be in cache more than
> Â Â Âthe previously scattered bits and pieces
> * more stack space is available for interrupts compared to 2.4 kernels
> Â Â- in 2.4 kernels only 2Kb was available for interrupt context (to
> Â Â Âkeep 4K available for user context). With complex softirqs such as
> Â Â ÂPPP and firewall rules and nested interrupts this wasn't always
> Â Â Âenough. Compared to 2.6-with-8Kstacks is a bit harder; there is
> Â Â Â2Kb extra available there compared to 2.4 and arguably some of that
> Â Â Âextra is for interrupts.

This is due to having interrupt stacks. Is there any reason not to have
8K task stacks and per CPU interrupt stacks?


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at