On 13.11.2018 18:10, Timofey Titovets wrote:
You mean try do something, like that right?
read_lock(&tasklist_lock);
<get reference to task>
task_lock(task);
read_unlock(&tasklist_lock);
last_pid = task_pid_nr(task);
ksm_import_task_vma(task);
task_unlock(task);
No, task_lock() uses spin_lock() under the bonnet, so this will be the
same.
Since the sole reason you have to lock/acquire/get a reference to
task_struct here is to prevent it from disappearing, I was thinking
about using get_task_struct(), which just increases atomic
task_struct.usage value (IOW, takes a reference). I *hope* this will be
enough to prevent task_struct from disappearing in the meantime.
Someone, correct me if I'm wrong.
--
Oleksandr Natalenko (post-factum)
