Re: kmap_atomic

From: William Lee Irwin III
Date: Tue Nov 23 2004 - 01:04:23 EST


On Mon, Nov 22, 2004 at 03:54:24PM +0100, Brice Goglin wrote:
> I would like to know if I can use kmap_atomic with KM_USER[01] type
> within a non-interrupt context. Looking at comments near kmap_atomic
> declarations on sparc or ppc, it seems that this is discouraged.
> But lots of code (like filesystem stuff) are currently using it
> outside of interrupt context.
> Are there special requirements about KM_USER[01] usage in interrupt
> or non-interrupt contexts ?
> Is it documented somewhere how we can use it ?
> What I want to do is just kmap_atomic, copy and kunmap_atomic.

Those comments are stale. This varies by km_type. A given km_type may
only be used in one context. KM_USER0/KM_USER1 are specifically
dedicated to process context copying. KM_IRQ0/KM_IRQ1 are specifically
devoted to interrupt-context copying.


-- wli
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