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

Michal Hocko
2017-11-14T07:21:04Z

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?
--
Michal Hocko
SUSE Labs