Re: [PATCH] Use MPOL_INTERLEAVE for tmpfs files

From: Martin J. Bligh
Date: Tue Nov 09 2004 - 17:11:28 EST


--On Tuesday, November 09, 2004 21:08:11 +0000 Hugh Dickins <hugh@xxxxxxxxxxx> wrote:

> On Tue, 9 Nov 2004, Martin J. Bligh wrote:
>>
>> > I'm irritated to realize that we can't change the default for SysV
>> > shared memory or /dev/zero this way, because that mount is internal.
>>
>> Boggle. shmem I can perfectly understand, and have been intending to
>> change for a while. But why /dev/zero ? Presumably you'd always want
>> that local?
>
> I was meaning the mmap shared writable of /dev/zero, to get memory
> shared between parent and child and descendants, a restricted form
> of shared memory. I was thinking of them running on different cpus,
> you're suggesting they'd at least be on the same node. I dare say,
> I don't know. I'm not desperate to be able to set some other mpol
> default for all of them (and each object can be set in the established
> way), just would have been happier if the possibility of doing so came
> for free with the mount option work.

Oh yeah ... the anon mem allocator trick. Mmmm. Not sure that should
have a different default than normal alloced memory, but either way,
what you're suggesting makes a whole lot more sense to me know than
just straight /dev/zero ;-)

Thanks for the explanation.

M.

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