Re: [RFC 2/2] x86_64: expand kernel stack to 16K

Dave Chinner
2014-05-28T22:11:23Z

On Wed, May 28, 2014 at 07:23:23AM -0700, H. Peter Anvin wrote:
> We tried for 4K on x86-64, too, for b quite a while as I recall.
> The kernel stack is a one of the main costs for a thread. I would
> like to decouple struct thread_info from the kernel stack (PJ
> Waskewicz was working on that before he left Intel) but that
> doesn't buy us all that much.
>
> 8K additional per thread is a huge hit. XFS has indeed always
> been a canary, or troublespot, I suspect because it originally
> came from another kernel where this was not an optimization
> target.

<sigh>

Always blame XFS for stack usage problems.

Even when the reported problem is from IO to an ext4 filesystem.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com