Messages in this thread | | | Date | Mon, 5 Jun 2006 16:48:38 +0100 | From | Russell King <> | Subject | Re: [PATCHSET] block: fix PIO cache coherency bug, take 2 |
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On Mon, Jun 05, 2006 at 10:47:40AM -0500, James Bottomley wrote: > On Mon, 2006-06-05 at 16:34 +0100, Russell King wrote: > > What has zero copy (your reply) got to do with faulting pages into > > userspace (my message). I'm sorry, I don't understand why you've > > brought this up. > > The zero copy case is the case where we end up with user and kernel > mappings simultaneously on the page. The nopage (or fault) case is > where we end up with them sequentially. Both cases actually require the > same cache treatment, but it's easiest to understand in the zero copy > case.
When does the zero copy case occur?
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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