Re: [RFC PATCH 5/5 single-thread-version] implement per-domain single-threadstate machine call_srcu()

[Lai Jiangshan]

On 03/13/2012 02:03 AM, Paul E. McKenney wrote:

>>
>> In mb()-based srcu, synchronize_srcu() is very fast,
>> synchronize_srcu_expedited() makes less sense than before.
> 
> I am worried about expedited callbacks getting backed up behind
> non-expedited callbacks (especially given Peter's point about per-VMA
> SRCU callbacks) and behind other workqueue uses.
> 
>> But when wait_srcu_gp() is move back here, I will use
>> a bigger "trycount" for synchronize_srcu_expedited().
>>
>> And any problem for srcu_advance_batches()?
> 
> I prefer the use of "return" that you and Peter discussed later.
> 
> What sort of testing are you doing?
>

rcutorture in my box for several days on my daily used machine.

What would you prefer for next round of patches, single-thread or per-cpu?
I will send them soon.
(per-cpu approach will be also "batches, in-sleepable, reuse rcu_head"....)

I prefer the single-thread approach until high-callback-rate-per-domain-era
comes, but I don't know how long when it comes. Peter?

Thanks,
Lai
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/