Re: missing madvise functionality

[Nick Piggin]

Eric Dumazet wrote:
> On Wed, 04 Apr 2007 20:05:54 +1000
> Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:
>
> > > @@ -1638,7 +1652,7 @@ find_extend_vma(struct mm_struct * mm, u
> > > 	unsigned long start;
> > >
> > > 	addr &= PAGE_MASK;
> > > -	vma = find_vma(mm,addr);
> > > +	vma = find_vma(mm,addr,&current->vmacache);
> > > 	if (!vma)
> > > 		return NULL;
> > > 	if (vma->vm_start <= addr)
> >
> > So now you can have current calling find_extend_vma on someone else's mm
> > but using their cache. So you're going to return current's vma, or current
> > is going to get one of mm's vmas in its cache :P
>
>
> This was not a working patch, just to throw the idea, since the answers I got showed I was not understood.
>
> In this case, find_extend_vma() should of course have one struct vm_area_cache * argument, like find_vma()
>
> One single cache on one mm is not scalable. oprofile badly hits it on a dual cpu config.

Oh, what sort of workload are you using to show this? The only reason that I
didn't submit my thread cache patches was that I didn't show a big enough
improvement.

--
SUSE Labs, Novell Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/