Re: fix swapping on 8xx?
flat view
From: Marcelo Tosatti <hidden>
Date: 2005-11-09 17:25:40
On Tue, Nov 08, 2005 at 10:56:58AM -0700, Tom Rini wrote:
On Tue, Nov 08, 2005 at 01:59:26PM +0200, David Jander wrote:quoted
On Tuesday 08 November 2005 01:55, Dan Malek wrote:quoted
On Nov 7, 2005, at 10:10 AM, Marcelo Tosatti wrote:quoted
The following is an attempt to fix swapping on 8xx by not touching _PAGE_ACCESSED bit if the page is not present.Ugh .... I suppose. I hate assembler code macros ....... Somehow, "swapping" and "8xx" just don't belong together.Well, at least it sounds ugly together, but it is also at least conceiveable. There seem to be people who use PCMCIA for an IDE interface, so swapping may become desireable in some cases.I think Dan might be in the camp that says a properly designed embedded system won't need to swap. And when I hear about how people do try and swap on systems like this, I really start agreeing. Maybe we could make 8xx just select SWAP=n? :)
TimeSys shipped their kernel with swapping fix as far as I know (Jason plyed with it recently). We'd better not assume what people try to do with their old 8xx's :)
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I'm tempted to add a configuration option that is the complete opposite of this and assumes are really embedded system. Mark pages as always accessed, data pages as always dirty, and you can eliminate lots of TLB faults in systems that are fairly static.It sounds tempting indeed, but should you really notice a performance increase out of this?Compared to 8xx in 2.6 today? Absolutely. -- Tom Rini http://gate.crashing.org/~trini/ _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded