On 05/25/2010 11:16 AM, Avi Kivity wrote:
On 05/25/2010 06:01 PM, Anthony Liguori wrote:
On 05/25/2010 10:00 AM, Avi Kivity wrote:
The latter. Why is it less important? If you don't inherit the
memory, you can't access it.
You can also pass /dev/shm fd's via SCM_RIGHTs to establish shared
memory segments dynamically.
Doesn't work for anonymous memory.
What's wrong with /dev/shm memory?
The kernel treats anonymous and nonymous memory differently for
swapping (see /proc/sys/vm/swappiness); transparent hugepages won't
work for /dev/shm (though it may be argued that that's a problem with
thp); setup (/dev/shm defaults to half memory IIRC, we want mem+swap);
different cgroup handling; somewhat clunky (a minor concern to be sure).
Surely, with mmu notifiers, it wouldn't be that hard to share anonymous
memory via an fd though, no?
Regards,
Anthony Liguori
Nothing is a killer, but we should prefer anonymous memory.
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