Re: [PATCH] add execute_in_process_context() API

[Tejun <htejun@gmail.com>]

James Bottomley wrote:
> On Wed, 2006-02-08 at 09:06 +0100, Andi Kleen wrote:
> 
>>In general this seems like a lot of code for a simple problem.
>>It might be simpler to just put the work structure into the parent
>>object and do the workqueue unconditionally
> 
> 
> We can't do this.  For the target release, there may be multiple calls
> to the reap function ... if we embed in the structure we have no room
> for more than one.
> 
> 
>>>+	if (unlikely(!wqw)) {
>>>+		printk(KERN_ERR "Failed to allocate memory\n");
>>>+		WARN_ON(1);
>>
>>WARN_ON for GFP_ATOMIC failure is bad. It is not really a bug.
> 
> 
> Here, it means that the requested work wasn't executed.  In SCSI that
> would mean an object is now in place permanently.  The problem is that
> there's no real way to cope with failure in this case.
> 

Hi, James.

I haven't really looked at the code carefully, but I think one work 
struct + atomic counter (say pending_reap_cnt) should do it. 
queue_work() guarantees the work is run at least once after the call, so 
bumping pending_reap_cnt and queueing the work in target reap and 
reaping pending_reap_cnt times in the work should work.

-- 
tejun