Re: mutex vs cache coherency protocol

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



what about the kernel?  How will it protect itself when multiple 
processors execute kernel code???


Robert M. Hyatt, Ph.D.          Computer and Information Sciences
hyatt@xxxxxxx                   University of Alabama at Birmingham
(205) 934-2213                  136A Campbell Hall
(205) 934-5473 FAX              Birmingham, AL 35294-1170

On Mon, 3 Sep 2007, Xu Yang wrote:

> Hello everyone,
> 
> Just got a rough question in my head.
> 
> don't know whether anyone interested .
> 
> mutex vs cache coherency protocol(for multiprocessor)
> 
> both of these two can be used to protect shared resource in the memory.
> 
> are both of them necessary?
> 
> for example:
> 
> in a multiprocessor system, if there is only mutex no cache coherency.
> obviously this would cause problem.
> 
> what about there is no mutex mechanism, only cache coherency protocol
> in multiprocessor system? after consideration, I found this also could
> casue problem, when the processors are multithreading processors,
> which means more than one threads can be running on one processor. in
> this case if we only have cache coherency and no mutex, this would
> cause problem. because all the threads running on one processor share
> one cache, the cache coherency protocol can not be functioning
> anymore. the shrared resource could be crashed by different threads.
> 
> then if all the processors in the multiprocessor system are sigle
> thread processor, only one thread can be running one one processor. is
> it ok, if we only have cache coherency protocol ,no mutex mechanism?
> 
> anyone has any idea? all the comments are welcome and appreciated,
> including criticism.
> 
> regards,
> -
> To unsubscribe from this list: send the line "unsubscribe linux-smp" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
-
To unsubscribe from this list: send the line "unsubscribe linux-smp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Kernel]     [Remote Processor]     [Audio]     [Linux for Hams]     [Kernel Newbies]     [Netfilter]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Fedora Users]

  Powered by Linux