RE: [linuxppc-release] [PATCH 1/2] powerpc, e5500: add networking to defconfig

Subject: Re: [linuxppc-release] [PATCH 1/2] powerpc, e5500: add networking
to defconfig

On Thu, 12 May 2011 10:31:08 -0500
Scott Wood [off-list ref] wrote:

quoted

On Thu, 12 May 2011 01:11:03 -0500
Li Yang-R58472 [off-list ref] wrote:

quoted

quoted

diff --git a/arch/powerpc/configs/e55xx_smp_defconfig

b/arch/powerpc/configs/e55xx_smp_defconfig
index 9fa1613..f4c5780 100644

--- a/arch/powerpc/configs/e55xx_smp_defconfig
+++ b/arch/powerpc/configs/e55xx_smp_defconfig

@@ -6,10 +6,10 @@ CONFIG_NR_CPUS=3D2

CONFIG_EXPERIMENTAL=3Dy
CONFIG_SYSVIPC=3Dy
CONFIG_BSD_PROCESS_ACCT=3Dy
+CONFIG_SPARSE_IRQ=3Dy

Hi Scott,

I remember in previous testing that this option has a negative effect

on performance.  Do we really need it to be enabled?

quoted

I didn't change this setting, it just moved due to running it through
savedefconfig.

What was the performance impact?

It adds CPU cycles to the interrupt handling path.  Will cause performance =
drop for benchmarks with large amount of interrupts such as IP forwarding.

- Leo