Re: distributed shared memory / mmap

From: Steven Whitehouse
Date: Wed Aug 20 2008 - 10:45:41 EST


Hi,

On Wed, 2008-08-20 at 15:18 +0200, Martin Uecker wrote:
>
> Hi!
>
> Is there any easy way to get shared memory between to
> processes on different machines? It seems possible using mmap
> on a file system like GFS on top of a distributed block device.
>
>
> Sincerly,
> Martin Uecker
>
Yes, you can do it using GFS/GFS2 and it should work. On the other hand,
don't do it. Its probably not what you want and unlikely to give you
good performance since the locking is "per inode" and thus you'll
generate a lot of cache flushing if there is any appreciable amount of
writing to the shared region. If you have a read mostly (or only)
workload, then it will work much better.

There are often better solutions though, depending on the application in
question,

Steve.



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