Re: [PATCH] - Reduce TLB flushing during process migration

[Andrew Morton <akpm@osdl.org>]

Jack Steiner <steiner@sgi.com> wrote:
>
> On Wed, Jun 23, 2004 at 02:33:18PM -0700, Andrew Morton wrote:
> > Jack Steiner <steiner@sgi.com> wrote:
> > >
> > > This patch adds a platform specific hook to allow an arch-specific
> > > function to be called after an explicit migration.
> > 
> > OK by me.  David, could you please merge this up?
> > 
> > Jack, please prepare an update for Documentation/cachetlb.txt.
> 
> 
> ...
> +7) void tlb_migrate_finish(struct mm_struct *mm)
> +
> +	This interface is called at the end of an explicit
> +	process migration. This interface provides a hook 
> +	to allow a platform to update TLB or context-specific 
> +	information for the address space.
> +
> +	The ia64 sn2 platform is one example of a platform
> +	that uses this interface.

Ok...  But the code is still calling flush_tlb_mm() from within
set_cpus_allowed() on non-ia64 platforms, which I believe is unnecessary.

And it's calling it with a null pointer for kernel threads, which oopses on
i386.  We went over this weeks ago.

Shouldn't asm-generic.h be doing

	#define tlb_migrate_finish(mm)	do {} while (0)

?