Messages in this thread | | | Date | Tue, 20 Dec 2011 13:07:44 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [PATCH] VFS: br_write_lock locks on possible CPUs other than online CPUs |
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On 12/20/2011 01:00 PM, mengcong wrote:
> On Tue, 2011-12-20 at 06:27 +0000, Al Viro wrote: >> On Tue, Dec 20, 2011 at 10:26:05AM +0530, Srivatsa S. Bhat wrote: >>> Oh, right, that has to be handled as well... >>> >>> Hmmm... How about registering a CPU hotplug notifier callback during lock init >>> time, and then for every cpu that gets onlined (after we took a copy of the >>> cpu_online_mask to work with), we see if that cpu is different from the ones >>> we have already locked, and if it is, we lock it in the callback handler and >>> update the locked_cpu_mask appropriately (so that we release the locks properly >>> during the unlock operation). >>> >>> Handling the newly introduced race between the callback handler and lock-unlock >>> code must not be difficult, I believe.. >>> >>> Any loopholes in this approach? Or is the additional complexity just not worth >>> it here? >> >> To summarize the modified variant of that approach hashed out on IRC: >> > On which IRC do you discuss?
#kernel on tinc.sekrit.org :-)
Regards, Srivatsa S. Bhat
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