Re: [PATCH] futex: bugfix for futex-key conflict when futex use hugepage

Darren Hart
2013-04-16T18:47:57Z

On 04/16/2013 11:37 AM, Dave Hansen wrote:
> Instead of bothering to store the index, why not just calculate it, like:
>
> On 04/15/2013 08:37 PM, zhang.yi20@zte.com.cn wrote:
>> +static inline int get_page_compound_index(struct page *page)
>> +{
>> + if (PageHead(page))
>> + return 0;
>> + return compound_head(page) - page;
>> +}
>
> BTW, you've really got to get your mail client fixed. Your patch is
> still line-wrapped.

And with this it would no longer be necessary to store this index at
all, eliminating all changes to the MM other than this accessor function
- which if not needed there could be added to futex.c, or even replaced with
"page_head - page" in get_futex_key() right?

--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Technical Lead - Linux Kernel