linux/arch/mips
Mateusz Guzik c8afaa1b0f locking: remove spin_lock_prefetch
The only remaining consumer is new_inode, where it showed up in 2001 as
commit c37fa164f793 ("v2.4.9.9 -> v2.4.9.10") in a historical repo [1]
with a changelog which does not mention it.

Since then the line got only touched up to keep compiling.

While it may have been of benefit back in the day, it is guaranteed to
at best not get in the way in the multicore setting -- as the code
performs *a lot* of work between the prefetch and actual lock acquire,
any contention means the cacheline is already invalid by the time the
routine calls spin_lock().  It adds spurious traffic, for short.

On top of it prefetch is notoriously tricky to use for single-threaded
purposes, making it questionable from the get go.

As such, remove it.

I admit upfront I did not see value in benchmarking this change, but I
can do it if that is deemed appropriate.

Removal from new_inode and of the entire thing are in the same patch as
requested by Linus, so whatever weird looks can be directed at that guy.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/fs/inode.c?id=c37fa164f793735b32aa3f53154ff1a7659e6442 [1]
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-08-12 09:18:47 -07:00
..
alchemy TTY/Serial driver updates for 6.5-rc1. 2023-07-03 13:14:58 -07:00
ar7 mips: ar7: include linux/gpio/driver.h 2023-03-10 13:40:18 +02:00
ath25 MIPS: ath25: Constify static irq_domain_ops 2022-02-22 09:39:03 +01:00
ath79 MIPS: ath79: remove obsolete ATH79_DEV_* configs 2023-03-17 10:28:04 +01:00
bcm47xx MIPS: BCM47XX: Add support for Huawei B593u-12 2023-03-14 17:05:14 +01:00
bcm63xx MIPS: BCM63xx: Add check for NULL for clk in clk_enable 2022-12-09 23:37:06 +01:00
bmips mips: update a reference to a moved Arm Document 2023-06-13 03:47:20 -06:00
boot MIPS: dts: add missing space before { 2023-07-06 13:55:43 +02:00
cavium-octeon - added support for TP-Link HC220 G5 v1 2023-06-29 15:01:51 -07:00
cobalt
configs arch/*/configs/*defconfig: Replace AUTOFS4_FS by AUTOFS_FS 2023-07-29 14:08:22 -07:00
crypto crypto: Kconfig - simplify cipher entries 2022-08-26 18:50:43 +08:00
dec MIPS: fix typos in comments 2022-05-04 22:22:59 +02:00
fw MIPS: fw: Allow firmware to pass a empty env 2023-04-12 15:07:36 +02:00
generic mips: ingenic: Enable EXT/2 divider on JZ4750/55/60 if EXT is 24 MHz 2023-06-09 09:54:17 +02:00
include locking: remove spin_lock_prefetch 2023-08-12 09:18:47 -07:00
ingenic
jazz MIPS: fix typos in comments 2022-05-04 22:22:59 +02:00
kernel - fixes for KVM 2023-07-09 10:02:49 -07:00
kvm MIPS: kvm: Fix build error with KVM_MIPS_DEBUG_COP0_COUNTERS enabled 2023-07-07 14:43:01 +02:00
lantiq MIPS: vpe-mt: drop physical_memsize 2023-02-20 15:11:01 +01:00
lib MIPS: Simplify __bswapdi2() and __bswapsi2() 2022-09-30 16:50:00 +02:00
loongson2ef MIPS: loongson2ef: Add missing break in cs5536_isa 2023-04-12 15:12:24 +02:00
loongson32 - added support for TP-Link HC220 G5 v1 2023-06-29 15:01:51 -07:00
loongson64 MIPS: SMP_CPS: Switch to hotplug core state synchronization 2023-05-15 13:44:58 +02:00
math-emu MIPS: Fix comment typo 2022-09-12 15:33:24 +02:00
mm - added support for TP-Link HC220 G5 v1 2023-06-29 15:01:51 -07:00
mti-malta MIPS: Remove deprecated CONFIG_MIPS_CMP 2023-04-12 15:01:09 +02:00
n64
net bpf, mips: Implement R4000 workarounds for JIT 2023-02-28 14:52:55 +01:00
pci mips: pci-mt7620: use dev_info() to log PCIe device detection result 2023-06-21 14:53:45 +02:00
pic32 MIPS: pic32: treat port as signed integer 2022-11-11 15:53:58 +01:00
power
ralink mips: ralink: match all supported system controller compatible strings 2023-06-23 15:00:37 +02:00
rb532 MIPS: rb532: move GPIOD definition into C-files 2022-03-30 20:26:26 +02:00
sgi-ip22 driver core: make struct bus_type.uevent() take a const * 2023-01-27 13:45:52 +01:00
sgi-ip27 MIPS: SGI-IP27: Fix platform-device leak in bridge_platform_create() 2022-09-19 16:33:27 +02:00
sgi-ip30 MIPS: SGI-IP30: Fix platform-device leak in bridge_platform_create() 2022-09-19 16:32:54 +02:00
sgi-ip32
sibyte mips: Fix spacing issue 2023-06-09 09:49:59 +02:00
sni
tools MIPS: fix typos in comments 2022-05-04 22:22:59 +02:00
txx9 MIPS: fix typos in comments 2022-05-04 22:22:59 +02:00
vdso vdso: Improve cmd_vdso_check to check all dynamic relocations 2023-03-21 21:15:34 +01:00
Kbuild kbuild: remove --include-dir MAKEFLAG from top Makefile 2023-02-05 18:51:22 +09:00
Kbuild.platforms MIPS: sibyte: Remove unused config option SIBYTE_BCM1x55 2023-03-17 10:27:08 +01:00
Kconfig - added support for TP-Link HC220 G5 v1 2023-06-29 15:01:51 -07:00
Kconfig.debug
Makefile - fixes for KVM 2023-07-09 10:02:49 -07:00
Makefile.postlink kbuild: remove --include-dir MAKEFLAG from top Makefile 2023-02-05 18:51:22 +09:00