# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID f887ddae2b03ab363278afc92225aa3bc320de5f
# Parent 877d738e7a4005bee085bb42341b9d754e8eb978
Remove CONFIG_PREEMPT configuration option from Xen kernel builds.
The option reduces overall system performance and makes little sense
when running over a preemptive hypervisor. Removing the option also
fixes some hypothetical races.
The forthcoming voluntary-preemption option will make much more sense
to enable when running over Xen.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_32
--- a/linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_32 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_32 Thu Nov
24 19:01:16 2005
@@ -35,7 +35,6 @@
# CONFIG_CLEAN_COMPILE is not set
CONFIG_BROKEN=y
CONFIG_BROKEN_ON_SMP=y
-CONFIG_LOCK_KERNEL=y
CONFIG_INIT_ENV_ARG_LIMIT=32
#
@@ -125,8 +124,6 @@
# CONFIG_HPET_TIMER is not set
# CONFIG_HPET_EMULATE_RTC is not set
# CONFIG_SMP is not set
-CONFIG_PREEMPT=y
-CONFIG_PREEMPT_BKL=y
# CONFIG_X86_REBOOTFIXUPS is not set
CONFIG_MICROCODE=y
CONFIG_X86_CPUID=y
@@ -141,7 +138,6 @@
# CONFIG_HIGHMEM64G is not set
CONFIG_HIGHMEM=y
CONFIG_MTRR=y
-CONFIG_HAVE_DEC_LOCK=y
# CONFIG_REGPARM is not set
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
@@ -1259,7 +1255,6 @@
CONFIG_LOG_BUF_SHIFT=14
# CONFIG_SCHEDSTATS is not set
# CONFIG_DEBUG_SLAB is not set
-# CONFIG_DEBUG_PREEMPT is not set
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
# CONFIG_DEBUG_KOBJECT is not set
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
--- a/linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64 Thu Nov
24 19:01:16 2005
@@ -90,7 +90,6 @@
CONFIG_X86_GOOD_APIC=y
# CONFIG_HPET_TIMER is not set
# CONFIG_SMP is not set
-# CONFIG_PREEMPT is not set
CONFIG_MICROCODE=y
# CONFIG_X86_CPUID is not set
CONFIG_SWIOTLB=y
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_32
--- a/linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_32 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_32 Thu Nov
24 19:01:16 2005
@@ -125,8 +125,6 @@
CONFIG_SMP_ALTERNATIVES=y
CONFIG_NR_CPUS=8
# CONFIG_SCHED_SMT is not set
-CONFIG_PREEMPT=y
-CONFIG_PREEMPT_BKL=y
# CONFIG_X86_REBOOTFIXUPS is not set
CONFIG_X86_CPUID=y
@@ -550,7 +548,6 @@
CONFIG_LOG_BUF_SHIFT=14
# CONFIG_SCHEDSTATS is not set
# CONFIG_DEBUG_SLAB is not set
-# CONFIG_DEBUG_PREEMPT is not set
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
# CONFIG_DEBUG_KOBJECT is not set
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_64
--- a/linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_64 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xenU_defconfig_x86_64 Thu Nov
24 19:01:16 2005
@@ -92,7 +92,6 @@
CONFIG_SMP=y
CONFIG_NR_CPUS=8
# CONFIG_SCHED_SMT is not set
-# CONFIG_PREEMPT is not set
# CONFIG_MICROCODE is not set
CONFIG_X86_CPUID=y
# CONFIG_NUMA is not set
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_32
--- a/linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_32 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_32 Thu Nov
24 19:01:16 2005
@@ -132,8 +132,6 @@
CONFIG_SMP_ALTERNATIVES=y
CONFIG_NR_CPUS=8
# CONFIG_SCHED_SMT is not set
-CONFIG_PREEMPT=y
-CONFIG_PREEMPT_BKL=y
# CONFIG_X86_REBOOTFIXUPS is not set
CONFIG_MICROCODE=y
CONFIG_X86_CPUID=m
@@ -2951,7 +2949,6 @@
CONFIG_LOG_BUF_SHIFT=14
# CONFIG_SCHEDSTATS is not set
# CONFIG_DEBUG_SLAB is not set
-CONFIG_DEBUG_PREEMPT=y
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
# CONFIG_DEBUG_KOBJECT is not set
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_64
--- a/linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_64 Thu Nov
24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/configs/xen_defconfig_x86_64 Thu Nov
24 19:01:16 2005
@@ -95,7 +95,6 @@
CONFIG_SMP=y
CONFIG_NR_CPUS=8
# CONFIG_SCHED_SMT is not set
-# CONFIG_PREEMPT is not set
CONFIG_MICROCODE=y
# CONFIG_X86_CPUID is not set
# CONFIG_NUMA is not set
diff -r 877d738e7a40 -r f887ddae2b03 linux-2.6-xen-sparse/arch/xen/i386/Kconfig
--- a/linux-2.6-xen-sparse/arch/xen/i386/Kconfig Thu Nov 24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/Kconfig Thu Nov 24 19:01:16 2005
@@ -415,17 +415,17 @@
cost of slightly increased overhead in some places. If unsure say
N here.
-config PREEMPT
- bool "Preemptible Kernel"
- help
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
- This allows applications to run more reliably even when the system is
- under load.
-
- Say Y here if you are building a kernel for a desktop, embedded
- or real-time system. Say N if you are unsure.
+#config PREEMPT
+# bool "Preemptible Kernel"
+# help
+# This option reduces the latency of the kernel when reacting to
+# real-time or interactive events by allowing a low priority process to
+# be preempted even if it is in kernel mode executing a system call.
+# This allows applications to run more reliably even when the system is
+# under load.
+#
+# Say Y here if you are building a kernel for a desktop, embedded
+# or real-time system. Say N if you are unsure.
config PREEMPT_BKL
bool "Preempt The Big Kernel Lock"
diff -r 877d738e7a40 -r f887ddae2b03
linux-2.6-xen-sparse/arch/xen/x86_64/Kconfig
--- a/linux-2.6-xen-sparse/arch/xen/x86_64/Kconfig Thu Nov 24 18:49:15 2005
+++ b/linux-2.6-xen-sparse/arch/xen/x86_64/Kconfig Thu Nov 24 19:01:16 2005
@@ -224,21 +224,21 @@
If you don't know what to do here, say N.
-config PREEMPT
- bool "Preemptible Kernel"
- ---help---
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
- This allows applications to run more reliably even when the system is
- under load. On contrary it may also break your drivers and add
- priority inheritance problems to your system. Don't select it if
- you rely on a stable system or have slightly obscure hardware.
- It's also not very well tested on x86-64 currently.
- You have been warned.
-
- Say Y here if you are feeling brave and building a kernel for a
- desktop, embedded or real-time system. Say N if you are unsure.
+#config PREEMPT
+# bool "Preemptible Kernel"
+# ---help---
+# This option reduces the latency of the kernel when reacting to
+# real-time or interactive events by allowing a low priority process to
+# be preempted even if it is in kernel mode executing a system call.
+# This allows applications to run more reliably even when the system is
+# under load. On contrary it may also break your drivers and add
+# priority inheritance problems to your system. Don't select it if
+# you rely on a stable system or have slightly obscure hardware.
+# It's also not very well tested on x86-64 currently.
+# You have been warned.
+#
+# Say Y here if you are feeling brave and building a kernel for a
+# desktop, embedded or real-time system. Say N if you are unsure.
config SCHED_SMT
bool "SMT (Hyperthreading) scheduler support"
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home