Re: [PATCH 0/3] TLB flush multiple pages per IPI v5

Mel Gorman
2015-06-10T17:25:05Z

On Wed, Jun 10, 2015 at 09:42:34AM -0700, Linus Torvalds wrote:
> On Wed, Jun 10, 2015 at 9:17 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > So anyway, I like the patch series. I just think that the final patch
> > - the one that actually saves the addreses, and limits things to
> > BATCH_TLBFLUSH_SIZE, should be limited.
>
> Oh, and another thing:
>
> Mel, can you please make that "struct tlbflush_unmap_batch" be just
> part of "struct task_struct" rather than a pointer?
>

Yes, that was done earlier today based on Ingo's review so that the
allocation could be dealt with as a separate path at the end of the series.

> If you are worried about the cpumask size, you could use
>
> cpumask_var_t cpumask;
>
> and
>
> alloc_cpumask_var(..)
> ...
> free_cpumask_var(..)
>
> for that.
>
> That way, sane configurations never have the allocation cost.
>

Ok, good point. Patch 3 in my git tree ("mm: Dynamically allocate TLB
batch unmap control structure") does not do this but I'll look into doing
it before the release based on 4.2-rc1.

--
Mel Gorman
SUSE Labs