Messages in this thread | | | Date | Thu, 28 Apr 2011 15:48:25 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [PATCH 1/2] break out page allocation warning code |
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On Wed, 27 Apr 2011, john stultz wrote:
> So thinking further, this can be simplified by adding the seqlock first, > and then retaining the task_locking only in the set_task_comm path until > all comm accessors are converted to using get_task_comm. >
On second thought, I think it would be better to just retain using a spinlock but instead of using alloc_lock, introduce a new spinlock to task_struct for the sole purpose of protecting comm.
And, instead, of using get_task_comm() to write into a preallocated buffer, I think it would be easier in the vast majority of cases that you'll need to convert to just provide task_comm_lock(p) and task_comm_unlock(p) so that p->comm can be dereferenced safely. get_task_comm() could use that interface itself and then write into a preallocated buffer.
The problem with using get_task_comm() everywhere is it requires 16 additional bytes to be allocated on the stack in hundreds of locations around the kernel which may or may not be safe.
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