linux_dsm_epyc7002/arch/x86
Suravee Suthikulpanit f125be1469 oprofile/x86: implement lsfr pseudo-random number generator for IBS
This patch implements a linear feedback shift register (LFSR) for
pseudo-random number generation for IBS.

For IBS measurements it would be good to minimize memory traffic in
the interrupt handler since every access pollutes the data
caches. Computing a maximal period LFSR just needs shifts and ORs.

The LFSR method is good enough to randomize the ops at low
overhead. 16 pseudo-random bits are enough for the implementation and
it doesn't matter that the pattern repeats with a fairly short
cycle. It only needs to break up (hard) periodic sampling behavior.

The logic was designed by Paul Drongowski.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-02-26 15:14:02 +01:00
..
boot x86: add support for LZO-compressed kernels 2010-01-11 09:34:05 -08:00
configs tracing: Rename FTRACE_SYSCALLS for tracepoints 2009-08-26 00:17:35 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-12-01 15:16:22 +08:00
ia32 x86: get rid of the insane TIF_ABI_PENDING bit 2010-01-29 08:22:01 -08:00
include/asm x86-32: Make AT_VECTOR_SIZE_ARCH=2 2010-02-09 16:05:08 -08:00
kernel Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-11 14:01:10 -08:00
kvm KVM: PIT: control word is write-only 2010-02-09 19:20:15 +02:00
lguest lguest: move panic notifier registration to its expected place. 2009-09-23 22:26:44 +09:30
lib Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
math-emu
mm Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-11 14:01:10 -08:00
oprofile oprofile/x86: implement lsfr pseudo-random number generator for IBS 2010-02-26 15:14:02 +01:00
pci x86/PCI: remove IOH range fetching 2010-01-28 08:24:11 -08:00
power hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00
tools Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
vdso sysctl x86: Remove dead binary sysctl support 2009-11-12 02:05:04 -08:00
video
xen x86: xen: 64-bit kernel RPL should be 0 2010-01-13 11:23:54 +01:00
Kbuild
Kconfig x86: Remove "x86 CPU features in debugfs" (CONFIG_X86_CPU_DEBUG) 2010-01-23 18:27:47 -08:00
Kconfig.cpu Revert "x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium" 2010-01-05 16:01:35 -08:00
Kconfig.debug Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-11 20:47:30 -08:00
Makefile Merge branch 'perf/core' into perf/probes 2009-11-17 10:17:47 +01:00
Makefile_32.cpu Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:38:11 -08:00