Re: FW: Delayed Xaction and LOCK#

[Mark Gonzales <markg@scic.intel.com>]

d_schneider@emulex.com writes
>> From: "Monish Shah" <monish@mcsy2.fc.hp.com>
>> Message-Id: <9608270951.ZM7619@hpfcmss.fc.hp.com>
>> use of LOCK# should be avoided if at all possible.
>
>This could be a problem for us software types.  The LOCK# signal is 
>typically used for our mutual exclusion schemes (dining philosophers and all 
>that).  If we can't guarantee LOCK#, especially in a multi-master 
>environment, what is the recommended way of doing mutual exclusion?

Just use locations in main memory for your CPUs' semaphores.  You will
get excruciatingly bad performance if you attempt to synchronize many
CPUs by using locked CPU accesses to a semaphore in memory that resides
on the PCI bus.

Do you really have a product that has *PCI* masters that are
synchronizing amongst themselves using locked accesses to a semaphore?!?

--
Mark Gonzales.
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