Re: 2.6.16-rc6-mm2

Andi Kleen
2006-06-12T12:14:16Z

Ingo Molnar <mingo@elte.hu> writes:

> * Ingo Molnar <mingo@elte.hu> wrote:
>
> >
> > * Christoph Lameter <clameter@sgi.com> wrote:
> >
> > > Sorry that patch was still against mm1. Here is a fixed up version
> > > that applies cleanly against mm2:
> >
> > i have applied both patches you sent in this thread but it still
> > triggers tons of messages:
>
> > trying to fix it i realized that i'd have to touch tons of
> > architectures, which all duplicate this piece of code:
>
> below is an updated patch that includes fixups for i386 - but the real
> fix should be to properly reduce the per-arch local.h footprint to the
> bare minimum possible, and to do this fix on the asm-generic headers.

I think an even better approach would be to use local_save_flags() /
local_restore_flags () and then use a normal increment and get
rid of smp_processor_id completely.

I've never seen any evidence that the complex and bloated code generated by
this is any better that just enabling/disabling interrupts.

In the x86 world P4 has costly cli/sti, but I wouldn't expect
that problem to be very widespread.

-Andi