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Nicholas Piggin 9c7bfc2dc2 powerpc/64s: Make POWER10 and later use pause_short in cpu_relax loops
We want to move away from using SMT priority updates for cpu_relax, and
use a 'wait' instruction which is similar to x86. As well as being a
much better fit for what everybody else uses and tests with, priority
nops are stateful which is nasty (interrupts have to consider they might
be taken at a different priority), and they're expensive to execute,
similar to a mtSPR which can effect other threads in the pipe.

This has shown to give results that are less affected by code alignment
on benchmarks that cause a lot of spin waiting (e.g., rwsem contention
on unixbench filesystem benchmarks) on POWER10.

QEMU TCG only supports this instruction correctly since v7.1, versions
without the fix may cause hangs whne running POWER10 CPUs.

Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix checkpatch warnings RE the macros]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920122259.363092-2-npiggin@gmail.com
2022-09-28 19:22:10 +10:00
arch powerpc/64s: Make POWER10 and later use pause_short in cpu_relax loops 2022-09-28 19:22:10 +10:00
block block-6.0-2022-08-19 2022-08-20 10:17:05 -07:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation Documentation: Rename PPC_FSL_BOOK3E to PPC_E500 2022-09-26 23:00:13 +10:00
drivers watchdog: booke_wdt: Replace PPC_FSL_BOOK3E by PPC_E500 2022-09-26 23:00:13 +10:00
fs 5 cifs/smb3 fixes, one for stable 2022-08-21 10:21:16 -07:00
include asm-generic: compat: Support BE for long long args in 32-bit ABIs 2022-09-26 23:00:15 +10:00
init powerpc/64: Remove PPC64 special case for cputime accounting default 2022-09-05 14:14:27 +10:00
io_uring io_uring/net: use right helpers for async_data 2022-08-18 07:27:20 -06:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Various fixes for tracing: 2022-08-21 14:49:42 -07:00
lib lib/cpumask: drop always-true preprocessor guard 2022-08-15 11:00:44 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm - hugetlb_vmemmap cleanups from Muchun Song 2022-08-10 11:18:00 -07:00
net tcp: handle pure FIN case correctly 2022-08-18 11:04:56 -07:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts asm goto: eradicate CC_HAS_ASM_GOTO 2022-08-21 10:06:28 -07:00
security hardening fixes for v6.0-rc2 2022-08-19 13:56:14 -07:00
sound sound fixes for 6.0-rc2 2022-08-19 09:46:11 -07:00
tools powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers 2022-09-28 19:22:08 +10:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device() 2022-08-19 04:05:43 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS 5 cifs/smb3 fixes, one for stable 2022-08-21 10:21:16 -07:00
Makefile Linux 6.0-rc2 2022-08-21 17:32:54 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.