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

From: zhang . yi20
Date: Wed Apr 17 2013 - 05:56:16 EST


Darren Hart <dvhart@xxxxxxxxxxxxxxx> wrote on 2013/04/17 01:57:10:

> Again, a functional testcase in futextest would be a good idea. This
> helps validate the patch and also can be used to identify regressions in
> the future.

I will post the testcase code later.

>
> What is the max value of comp_idx? Are we at risk of truncating it?
> Looks like not really from my initial look.
>
> This also needs a comment in futex.h describing the usage of the offset
> field in union futex_key as well as above get_futex_key describing the
> key for shared mappings.
>
>

As far as I know , the max size of one hugepage is 1 GBytes for x86 cpu.
Can some other cpus support greater hugepage even more than 4 GBytes? If
so, we can change the type of 'offset' from int to long to avoid
truncating.
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