Patchwork powerpc: disable SPARSE_IRQ by default

mail settings
Submitter Yang Li
Date June 29, 2010, 9:32 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/57256/
State Accepted, archived
Commit b354e421c67dd52e5c86c62e04ce582535ac2779
Delegated to: Benjamin Herrenschmidt
Headers show


Yang Li - June 29, 2010, 9:32 a.m.
The SPARSE_IRQ considerably adds overhead to critical path of IRQ
handling.  However it doesn't benefit much in space for most systems with
limited IRQ_NR.  Should be disabled unless really necessary.

Signed-off-by: Li Yang <>
 arch/powerpc/Kconfig |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 328774b..6506bf4 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -400,7 +400,7 @@  config IRQ_ALL_CPUS
 config SPARSE_IRQ
 	bool "Support sparse irq numbering"
-	default y
+	default n
 	  This enables support for sparse irqs. This is useful for distro
 	  kernels that want to define a high CONFIG_NR_CPUS value but still
@@ -409,7 +409,7 @@  config SPARSE_IRQ
 	  ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 	    out the irq_desc[] array in a more NUMA-friendly way. )
-	  If you don't know what to do here, say Y.
+	  If you don't know what to do here, say N.
 config NUMA
 	bool "NUMA support"