On 02/26/2013 07:04 PM, Lai Jiangshan wrote: > On Tue, Feb 26, 2013 at 3:26 AM, Srivatsa S. Bhat > <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote: >> Hi Lai, >> >> On 02/25/2013 09:23 PM, Lai Jiangshan wrote: >>> Hi, Srivatsa, >>> >>> The target of the whole patchset is nice for me. >> >> Cool! Thanks :-) >> >>> A question: How did you find out the such usages of >>> "preempt_disable()" and convert them? did all are converted? >>> >> >> Well, I scanned through the source tree for usages which implicitly >> disabled CPU offline and converted them over. > > How do you scan? could you show the way you scan the source tree. > I can follow your instructions for double checking. > Its nothing special. I grepped the source tree for anything dealing with cpu_online_mask or its derivatives and also for functions/constructs that rely on the cpumasks internally (eg: smp_call_function). Then I audited all such call-sites and converted them (if needed) accordingly. >> Its not limited to uses >> of preempt_disable() alone - even spin_locks, rwlocks, local_irq_disable() >> etc also help disable CPU offline. So I tried to dig out all such uses >> and converted them. However, since the merge window is open, a lot of >> new code is flowing into the tree. So I'll have to rescan the tree to >> see if there are any more places to convert. > > I remember some code has such assumption: > preempt_disable() (or something else) > //the code assume that the cpu_online_map can't be changed. > preempt_enable() > > It is very hard to find out all such kinds of assumptions and fixes them. > (I notice your code mainly fixes code around send_xxxx()) > The conversion can be carried out using the method I mentioned above. Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
