kernel-fxtec-pro1x/arch/x86
Ingo Molnar 0d12cdd5f8 sched: improve sched_clock() performance
in scheduler-intense workloads native_read_tsc() overhead accounts for
20% of the system overhead:

 659567 system_call                              41222.9375
 686796 schedule                                 435.7843
 718382 __switch_to                              665.1685
 823875 switch_mm                                4526.7857
 1883122 native_read_tsc                          55385.9412
 9761990 total                                      2.8468

this is large part due to the rdtsc_barrier() that is done before
and after reading the TSC.

But sched_clock() is not a precise clock in the GTOD sense, using such
barriers is completely pointless. So remove the barriers and only use
them in vget_cycles().

This improves lat_ctx performance by about 5%.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 16:48:19 +01:00
..
boot .gitignore updates 2008-10-30 11:38:45 -07:00
configs x86: remove irqbalance in kernel for 32 bit 2008-10-16 16:52:52 +02:00
crypto crypto: crc32c - Use Intel CRC32 instruction 2008-08-29 15:49:50 +10:00
ia32 compat: generic compat get/settimeofday 2008-10-16 11:21:33 -07:00
include/asm sched: improve sched_clock() performance 2008-11-08 16:48:19 +01:00
kernel Revert "x86: default to reboot via ACPI" 2008-11-06 16:05:06 +01:00
kvm KVM: Fix guest shared interrupt with in-kernel irqchip 2008-10-28 14:21:34 +02:00
lguest lguest: fix irq vectors. 2008-10-31 11:24:28 +11:00
lib Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D 2008-10-11 20:23:20 +02:00
mach-default Merge branches 'x86/prototypes', 'x86/x2apic' and 'x86/debug' into x86/core 2008-08-14 14:58:22 +02:00
mach-generic x86: make 32bit support per_cpu vector 2008-10-16 16:52:53 +02:00
mach-rdc321x removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
mach-voyager x86, voyager: fix smp_intr_init() compile breakage 2008-11-03 10:52:21 +01:00
math-emu x86: coding style fixes to arch/x86/math-emu/reg_constant 2008-06-18 15:00:13 +02:00
mm Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-11-06 15:57:24 -08:00
oprofile oprofile: fixing whitespaces in arch/x86/oprofile/* 2008-10-16 17:17:46 +02:00
pci x86/PCI: irq and pci_ids patch for Intel Ibex Peak DeviceIDs 2008-10-20 10:53:48 -07:00
power Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D 2008-10-11 20:23:20 +02:00
vdso Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
video x86: video/fbdev.c: add MODULE_LICENSE 2008-05-04 20:04:46 +02:00
xen Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-10-28 09:52:25 -07:00
Kconfig Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-11-06 15:57:24 -08:00
Kconfig.cpu x86, bts: improve help text for BTS config 2008-10-28 16:39:37 +01:00
Kconfig.debug x86: usb debug port early console, fix 2008-07-26 17:32:30 +02:00
Makefile x86, um: ... and asm-x86 move 2008-10-22 22:55:20 -07:00
Makefile_32.cpu x86: merge winchip-2 and winchip-2a cpu choices 2008-10-13 10:22:48 +02:00