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

Arjan van de Ven
2005-11-14T11:19:40Z

On Mon, 2005-11-14 at 12:11 +0100, Jens Axboe wrote:
> On Mon, Nov 14 2005, Arjan van de Ven wrote:
> > On Mon, 2005-11-14 at 11:20 +0100, Pierre Ossman wrote:
> > > Adrian Bunk wrote:
> > > > It seems most problems with 4k stacks are already resolved.
> > > >
> > > > I'd like to see this patch to always use 4k stacks in -mm now for
> > > > finding any remaining problems before submitting this patch for 2.6.16.
> > > >
> > > >
> > >
> > > Has the block layer been remade to a serial approach?
> >
> > yes.
>
> Not in mainline it hasn't.

well the patch was for -mm ;)

>
> Are there any recent benchmarks of 4kb vs 8kb stacks?

not sure; I do know that it very much helps java (many more threads
possible) and the VM (far less order 1 allocs). In addition the 4Kb
allocation can be satisfied with the per cpu list of free 4Kb pages,
while obviously an order 1 cannot and has to go global.

> Is anyone shipping 4kb stack kernels?

Both Fedora and RHEL are shipping this for all 2.6 based versions (eg
FC2 and all later, RHEL4)