From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Will Newton <will.newton@gmail.com>
Cc: Luke Kenneth Casson Leighton <luke.leighton@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: advice sought: practicality of SMP cache coherency implemented in assembler (and a hardware detect line)
Date: Sat, 26 Mar 2011 12:08:47 +0000 [thread overview]
Message-ID: <20110326120847.71b6ae4d@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <AANLkTi=W0mW2o2muNgMnb1OQ6WaBeOmu1VBHr8Zf63r9@mail.gmail.com>
> Probably not. Is it a virtual or physical indexed cache? Do you have a
> precise workload in mind? If you have a very precise workload and you
> don't expect to get many write conflicts then it could be made to
> work.
I'm unconvinced. The user space isn't the hard bit - little user memory
is shared writable, the kernel data structures on the other hand,
especially in the RCU realm are going to be interesting.
> There are a number of mature cores out there that can do this already
> and can be bought off the shelf, I wouldn't underestimate the
> difficulty of getting your cache coherency protocol right particularly
> on a limited time/resource budget.
Architecturally you may want to look at running one kernel per device
(remembering that you can share the non writable kernel pages between
different instances a bit if you are careful) - and in theory certain
remote mappings.
Basically it would become a cluster with a very very fast "page transfer"
operation for moving data between nodes.
next prev parent reply other threads:[~2011-03-26 12:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-25 21:52 Luke Kenneth Casson Leighton
2011-03-25 22:41 ` Will Newton
2011-03-26 12:08 ` Alan Cox [this message]
2011-03-28 18:06 ` Paul E. McKenney
2011-03-28 18:48 ` Luke Kenneth Casson Leighton
2011-03-28 22:12 ` Paul E. McKenney
2011-03-28 22:18 ` Alan Cox
2011-03-28 23:38 ` Luke Kenneth Casson Leighton
2011-03-28 23:39 ` Luke Kenneth Casson Leighton
2011-03-28 23:53 ` Paul E. McKenney
2011-03-29 9:16 ` Alan Cox
2011-04-07 12:09 ` Luke Kenneth Casson Leighton
2011-04-08 16:24 ` Paul E. McKenney
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