[PATCH] iommu virtual merge no longer experimental
Benjamin Herrenschmidt
benh at au1.ibm.com
Wed Jul 18 06:56:26 EST 2007
On Tue, 2007-07-17 at 11:09 -0500, Linas Vepstas wrote:
> Per conversations with BenH, iommu virtual merging should no longer
> be considered to be an "experimental" feature. In particular,
> CONFIG_VMERGE has been set to "y" in te defconfigs for quite a while.
>
> Signed-off-by: Linas Vepstas <linas at austin.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> ----
> arch/powerpc/Kconfig | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> Index: linux-2.6.22-git2/arch/powerpc/Kconfig
> ===================================================================
> --- linux-2.6.22-git2.orig/arch/powerpc/Kconfig 2007-07-08 18:32:17.000000000 -0500
> +++ linux-2.6.22-git2/arch/powerpc/Kconfig 2007-07-17 11:08:18.000000000 -0500
> @@ -430,16 +430,17 @@ config MATH_EMULATION
> instructions to run.
>
> config IOMMU_VMERGE
> - bool "Enable IOMMU virtual merging (EXPERIMENTAL)"
> - depends on EXPERIMENTAL && PPC64
> - default n
> + bool "Enable IOMMU virtual merging"
> + depends on PPC64
> + default y
> help
> Cause IO segments sent to a device for DMA to be merged virtually
> by the IOMMU when they happen to have been allocated contiguously.
> This doesn't add pressure to the IOMMU allocator. However, some
> drivers don't support getting large merged segments coming back
> - from *_map_sg(). Say Y if you know the drivers you are using are
> - properly handling this case.
> + from *_map_sg().
> +
> + Most drivers don't have this problem; it is safe to say Y here.
>
> config HOTPLUG_CPU
> bool "Support for enabling/disabling CPUs"
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