Re: [PATCH 5/4] update ksm userspace interfaces

Gerd Hoffmann
2009-04-03T11:08:42Z

Izik Eidus wrote:
> Gerd Hoffmann wrote:
>> Did you test whenever it really cleans up in case you "kill -9 qemu"?
>>
>> I recently did something simliar with the result that the extra
>> reference hold on mm_struct prevented the process memory from being
>> zapped ...
>>
>> cheers,
>> Gerd
>>
> Did you use mmput() after you called get_task_mm() ???
> get_task_mm() do nothing beside atomic_inc(&mm->mm_users);

mmput() call was in ->release() callback, ->release() in turn never was
called because the kernel didn't zap the mappings because of the
reference ...

The driver *also* created mappings which ksmctl doesn't, so it could be
you don't run into this issue.

cheers,
Gerd