linux/include
David Woodhouse c02c52036e x86/i8253: Disable PIT timer 0 when not in use
commit 70e6b7d9ae upstream.

Leaving the PIT interrupt running can cause noticeable steal time for
virtual guests. The VMM generally has a timer which toggles the IRQ input
to the PIC and I/O APIC, which takes CPU time away from the guest. Even
on real hardware, running the counter may use power needlessly (albeit
not much).

Make sure it's turned off if it isn't going to be used.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhkelley@outlook.com>
Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-02-21 13:57:27 +01:00
..
acpi LoongArch: Fix warnings during S3 suspend 2025-02-08 09:52:27 +01:00
asm-generic Rename .data.once to .data..once to fix resetting WARN*_ONCE 2024-12-09 10:32:59 +01:00
clocksource x86/hyperv: Fix hv tsc page based sched_clock for hibernation 2025-01-10 14:31:36 +01:00
crypto crypto: ecc - Prevent ecc_digits_from_bytes from reading too many bytes 2025-01-09 13:31:52 +01:00
drm drm/connector: add mutex to protect ELD from concurrent access 2025-02-17 09:40:04 +01:00
dt-bindings dt-bindings: clock: sunxi: Export PLL_VIDEO_2X and PLL_MIPI 2025-02-08 09:51:55 +01:00
keys integrity: PowerVM support for loading third party code signing keys 2023-08-17 20:12:35 +00:00
kunit - An extensive rework of kexec and crash Kconfig from Eric DeVolder 2023-08-29 14:53:51 -07:00
kvm KVM: arm64: Fix host-programmed guest events in nVHE 2024-04-10 16:35:48 +02:00
linux x86/i8253: Disable PIT timer 0 when not in use 2025-02-21 13:57:27 +01:00
math-emu powerpc/math-emu: Remove -w build flag and fix warnings 2022-09-05 17:28:25 +10:00
media media: v4l2-core: v4l2-dv-timings: check cvt/gtf result 2024-12-09 10:32:51 +01:00
memory memory: renesas-rpc-if: Remove Runtime PM wrappers 2023-01-23 11:48:00 +01:00
misc cxl: fix typo in comment 2022-11-24 23:12:19 +11:00
net net: add dev_net_rcu() helper 2025-02-21 13:57:20 +01:00
pcmcia ARM: pxa/sa1100: move I/O space to PCI_IOBASE 2022-05-07 22:56:17 +02:00
ras mm, hwpoison: enable memory error handling on 1GB hugepage 2022-08-08 18:06:44 -07:00
rdma RDMA/core: Fix umem iterator when PAGE_SIZE is greater then HCA pgsz 2023-12-13 18:45:16 +01:00
rv rv: Reset per-task monitors also for idle tasks 2025-02-17 09:40:32 +01:00
scsi scsi: Remove scsi device no_start_on_resume flag 2024-10-17 15:24:11 +02:00
soc net: mscc: ocelot: be resilient to loss of PTP packets during transmission 2024-12-19 18:11:29 +01:00
sound ALSA: usb-audio: Update UMP group attributes for GTB blocks, too 2024-12-14 20:00:23 +01:00
target scsi: target: iscsi: Remove the unused netif_timeout attribute 2023-07-11 12:33:32 -04:00
trace rxrpc: Fix the rxrpc_connection attend queue handling 2025-02-17 09:40:13 +01:00
uapi Input: allocate keycode for phone linking 2025-02-17 09:40:10 +01:00
ufs scsi: ufs: core: Fix the HIGH/LOW_TEMP Bit Definitions 2025-02-17 09:40:20 +01:00
vdso vdso/bits.h: Add BIT_ULL() for the sake of consistency 2023-01-31 14:42:10 +01:00
video fbdev: stifb: Make the STI next font pointer a 32-bit signed offset 2023-11-28 17:19:58 +00:00
xen xen/events: reduce externally visible helper functions 2024-03-01 13:34:57 +01:00