Re: [PATCH] arch, mm: introduce arch_tlb_gather_mmu_lazy (was: Re: [RESEND PATCH] mm, oom_reaper: gather each vma to prevent) leaking TLB entry

Minchan Kim
2017-11-15T00:12:40Z

On Tue, Nov 14, 2017 at 08:21:00AM +0100, Michal Hocko wrote:
> On Tue 14-11-17 10:45:49, Minchan Kim wrote:
> [...]
> > Anyway, I think Wang Nan's patch is already broken.
> > http://lkml.kernel.org/r/%3C20171107095453.179940-1-wangnan0@huawei.com%3E
> >
> > Because unmap_page_range(ie, zap_pte_range) can flush TLB forcefully
> > and free pages. However, the architecture code for TLB flush cannot
> > flush at all by wrong fullmm so other threads can write freed-page.
>
> I am not sure I understand what you mean. How is that any different from
> any other explicit partial madvise call?

Argh, I misread his code. Sorry for that.