Messages in this thread | | | Date | Mon, 18 Feb 2008 19:52:28 +0100 | From | Andi Kleen <> | Subject | Re: Unable to continue testing of 2.6.25 |
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> I've yet to see a user who wants WC. Lets face it, WC *sucks*. This is why
Interesting.
> the folks who care about performance (the graphics guys) stopped using it.
I didn't know this. What do they do instead?
I understand that WC was added originally because AGP was really slow at IO towards the CPU. You mean on PCI-E it is fast enough now that standard cached WB works well enough?
> WC is slow, and on modern cpus leads to really bad performance. I'm really > half tempted to just ignore WC entirely and suggest that we don't even implement > it in the kernel. Yes it's really that bad.
At least the X server still uses it. In fact there are already some performance regression regarding this from differing kernel behavioun in the sysfs interfaces vs /dev/mem.
What would you recommend should the X server use instead? Always map standard WB? How about on older AGP systems?
-Andi
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