linux/arch/x86
James Morse a4846aaf39 x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow
The limbo and overflow code picks a CPU to use from the domain's list of online
CPUs. Work is then scheduled on these CPUs to maintain the limbo list and any
counters that may overflow.

cpumask_any() may pick a CPU that is marked nohz_full, which will either
penalise the work that CPU was dedicated to, or delay the processing of limbo
list or counters that may overflow. Perhaps indefinitely. Delaying the overflow
handling will skew the bandwidth values calculated by mba_sc, which expects to
be called once a second.

Add cpumask_any_housekeeping() as a replacement for cpumask_any() that prefers
housekeeping CPUs. This helper will still return a nohz_full CPU if that is the
only option. The CPU to use is re-evaluated each time the limbo/overflow work
runs. This ensures the work will move off a nohz_full CPU once a housekeeping
CPU is available.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-13-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2024-02-16 19:18:32 +01:00
..
boot x86/cleanups changes for v6.8: 2024-01-08 17:23:32 -08:00
coco - Add support managing TDX host hardware 2024-01-18 13:41:48 -08:00
configs hardening updates for v6.7-rc1 2023-10-30 19:09:55 -10:00
crypto This update includes the following changes: 2024-01-10 12:23:43 -08:00
entry asm-generic cleanups for 6.8 2024-01-10 18:13:44 -08:00
events Performance events changes for v6.8 are: 2024-01-08 19:37:20 -08:00
hyperv x86/cleanups changes for v6.8: 2024-01-08 17:23:32 -08:00
ia32
include x86/resctrl: Move CLOSID/RMID matching and setting to use helpers 2024-02-16 19:18:32 +01:00
kernel x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow 2024-02-16 19:18:32 +01:00
kvm Generic: 2024-01-17 13:03:37 -08:00
lib header cleanups for 6.8 2024-01-10 16:43:55 -08:00
math-emu
mm Many singleton patches against the MM code. The patch series which 2024-01-09 11:18:47 -08:00
net Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
pci pci-v6.8-changes 2024-01-17 16:23:17 -08:00
platform x86/cleanups changes for v6.8: 2024-01-08 17:23:32 -08:00
power
purgatory x86/purgatory: Remove LTO flags 2023-09-17 09:49:03 +02:00
ras
realmode x86/cleanups changes for v6.8: 2024-01-08 17:23:32 -08:00
tools x86/build changes for v6.8: 2024-01-08 17:22:02 -08:00
um This pull request contains the following changes for UML: 2024-01-17 10:44:34 -08:00
video fbdev: Replace fb_pgprotect() with pgprot_framebuffer() 2023-10-12 09:20:46 +02:00
virt x86/mce: Differentiate real hardware #MCs from TDX erratum ones 2023-12-12 08:46:46 -08:00
xen x86/cleanups changes for v6.8: 2024-01-08 17:23:32 -08:00
.gitignore
Kbuild
Kconfig IOMMU Updates for Linux v6.8 2024-01-18 15:16:57 -08:00
Kconfig.assembler x86/shstk: Add Kconfig option for shadow stack 2023-07-11 14:12:18 -07:00
Kconfig.cpu x86/Kconfig: Rework CONFIG_X86_PAE dependency 2023-12-19 13:03:06 +01:00
Kconfig.debug
Makefile Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
Makefile_32.cpu
Makefile.postlink kbuild: remove ARCH_POSTLINK from module builds 2023-10-28 21:10:08 +09:00
Makefile.um