linux/arch
Peter Zijlstra 3daa96d672 perf/intel: Remove Perfmon-v4 counter_freezing support
Perfmon-v4 counter freezing is fundamentally broken; remove this default
disabled code to make sure nobody uses it.

The feature is called Freeze-on-PMI in the SDM, and if it would do that,
there wouldn't actually be a problem, *however* it does something subtly
different. It globally disables the whole PMU when it raises the PMI,
not when the PMI hits.

This means there's a window between the PMI getting raised and the PMI
actually getting served where we loose events and this violates the
perf counter independence. That is, a counting event should not result
in a different event count when there is a sampling event co-scheduled.

This is known to break existing software (RR).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-27 17:26:58 +01:00
..
alpha local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
arc local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
arm local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
arm64 local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
c6x tif-task_work.arch-2020-12-14 2020-12-16 12:33:35 -08:00
csky local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
h8300 local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
hexagon local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
ia64 local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
m68k local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
microblaze local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
mips local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
nds32 local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
nios2 tif-task_work.arch-2020-12-14 2020-12-16 12:33:35 -08:00
openrisc local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
parisc local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
powerpc local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
riscv local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
s390 - Update defconfigs and sort config select list. 2021-01-02 12:22:46 -08:00
sh local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
sparc local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
um This pull request contains the following changes for UML: 2020-12-17 17:56:44 -08:00
x86 perf/intel: Remove Perfmon-v4 counter_freezing support 2021-01-27 17:26:58 +01:00
xtensa local64.h: make <asm/local64.h> mandatory 2020-12-29 15:36:49 -08:00
.gitignore
Kconfig kasan: allow VMAP_STACK for HW_TAGS mode 2020-12-22 12:55:08 -08:00