On 8/13/2013 7:29 PM, Tejun Heo wrote:
> Hello,
>
> On Tue, Aug 13, 2013 at 06:53:32PM -0400, Chris Metcalf wrote:
>> int lru_add_drain_all(void)
>> {
>> - return schedule_on_each_cpu(lru_add_drain_per_cpu);
>> + return schedule_on_each_cpu_cond(lru_add_drain_per_cpu,
>> + lru_add_drain_cond, NULL);
> It won't nest and doing it simultaneously won't buy anything, right?
Correct on both counts, I think.
> Wouldn't it be better to protect it with a mutex and define all
> necessary resources statically (yeah, cpumask is pain in the ass and I
> think we should un-deprecate cpumask_t for static use cases)? Then,
> there'd be no allocation to worry about on the path.
If allocation is a real problem on this path, I think this is probably
OK, though I don't want to speak for Andrew. You could just guard it
with a trylock and any caller that tried to start it while it was
locked could just return happy that it was going on.
I'll put out a version that does that and see how that looks
for comparison's sake.
--
Chris Metcalf, Tilera Corp.
http://www.tilera.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>