On 08/12, Michal Hocko wrote:

On Fri 12-08-16 15:21:41, Oleg Nesterov wrote:

quoted

Whats really interesting is that I still fail to understand do we really
need this hack, iiuc you are not sure too, and Michael didn't bother to
explain why a bogus zero from anon memory is worse than other problems
caused by SIGKKILL from oom-kill.c.

Yes, I admit that I am not familiar with the vhost memory usage model so
I can only speculate. But the mere fact that the mm is bound to a device
fd

Yes, and I already tried to complain. This doesn't look right in any case.

which can be passed over to a different process makes me worried.

This means that the mm is basically isolated from the original process
until the last fd is closed which is under control of the process which
holds it. The mm can still be access during that time from the vhost
worker. And I guess this is exactly where the problem lies.

Agreed.

Oleg.

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