[PATCH] D18422: Add Cache Pruning support

[Rafael Espíndola via llvm-commits]

On 24 March 2016 at 15:00, Mehdi Amini <mehdi.amini at apple.com> wrote:
>
>> On Mar 24, 2016, at 11:54 AM, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
>>
>> On 24 March 2016 at 13:20, Mehdi AMINI via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>>> joker.eph added a comment.
>>>
>>> This will not help with the access to `StatBuf.st_atime`.
>>
>> Note that atime is not very dependable. I think most linux systems
>> these days use relatime for example.
>
> Is it detectable? Could we "touch" the file to update mtime?

That relatime is not updated? I guess it is possible to write a test, yes.

The man page of mount says:

-----------------------------------------------------------------------------------
    relatime
              Update  inode  access times relative to modify or change
time.  Access time is only updated if the previous access time was
earlier than the current modify or change time.  (Similar to noatime,
but it doesn't break mutt or other applications that need to know if a
file has been
              read since the last time it was modified.)

              Since Linux 2.6.30, the kernel defaults to the behavior
provided by this option (unless noatime was specified), and the
strictatime option is required to obtain traditional semantics.  In
addition, since Linux 2.6.30, the file's last access time is always
updated if it is  more
              than 1 day old.
------------------------------------------------------------------------------

Aaron, is atime available on windows?

Cheers,
Rafael