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authorIngo Molnar <mingo@elte.hu>2006-02-17 13:52:44 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-17 13:59:26 -0800
commit4bbf39c29bc3409d6454faf0dfa1b3b0aa2ac2af (patch)
tree2f8ed8aa42a1645a9cb3306ce93c9e4b63536630 /arch
parent05efc67d100ff6c3364604b72729addf1a86fdab (diff)
[PATCH] Introduce CONFIG_DEFAULT_MIGRATION_COST
Heiko Carstens <heiko.carstens@de.ibm.com> wrote: The boot sequence on s390 sometimes takes ages and we spend a very long time (up to one or two minutes) in calibrate_migration_costs. The time spent there differs from boot to boot. Also the calculated costs differ a lot. I've seen differences by up to a factor of 15 (yes, factor not percent). Also I doubt that making these measurements make much sense on a completely virtualized architecture where you cannot tell how much cpu time you will get anyway. So introduce the CONFIG_DEFAULT_MIGRATION_COST method for an architecture to set the scheduler migration costs. This turns off automatic detection of migration costs. Makes sense on virtual platforms, where migration costs are hard to measure accurately. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/Kconfig4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b66602ad7b33..b7ca5bf9acfc 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -80,6 +80,10 @@ config HOTPLUG_CPU
can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
+config DEFAULT_MIGRATION_COST
+ int
+ default "1000000"
+
config MATHEMU
bool "IEEE FPU emulation"
depends on MARCH_G5