Re: [PATCH -rt] scheduling while atomic in fs/file.c

[Daniel Walker <dwalker@mvista.com>]

On Sun, 2006-05-14 at 12:44 -0400, Steven Rostedt wrote:
> On Sun, 14 May 2006, Daniel Walker wrote:
> 
> > Quite the smp_processor_id() wanrings. I don't see any SMP
> > concerns here . It just adds to a percpu list, so it shouldn't
> > matter if it switches after sampling fdtable_defer_list .
> 
> I'm not so sure that there isn't SMP concerns here. I have to catch a
> train in a few minutes, otherwise I would look deeper into this. But this
> might be a candidate to turn fdtable_defer_list into a per_cpu_locked.

I reviewed it again, and it looks like these percpu structures have a
spinlock to protect the list from being emptied by a work queue while
things are being added to the list . The lock appears to be used
properly .  The work queue frees struct fdtable pointers added to the
list , the only place these structures are added is in the block I've
modified .

I think making this a locked percpu would just be overkill ..

Daniel

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