diff mbox series

[110/147] arch: remove GENERIC_FIND_FIRST_BIT entirely

Message ID 20210908025907.YK9ww9N-v%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [001/147] mm, slub: don't call flush_all() from slab_debug_trace_open() | expand

Commit Message

Andrew Morton Sept. 8, 2021, 2:59 a.m. UTC 
From: Yury Norov <yury.norov@gmail.com>
Subject: arch: remove GENERIC_FIND_FIRST_BIT entirely

In 5.12 cycle we enabled GENERIC_FIND_FIRST_BIT config option for ARM64
and MIPS.  It increased performance and shrunk .text size; and so far I
didn't receive any negative feedback on the change.

https://lore.kernel.org/linux-arch/20210225135700.1381396-1-yury.norov@gmail.com/

Now I think it's a good time to switch all architectures to use
find_{first,last}_bit() unconditionally, and so remove corresponding
config option.

The patch does't introduce functioal changes for arc, arm, arm64, mips,
m68k, s390 and x86, for other architectures I expect improvement both in
performance and .text size.

Link: https://lkml.kernel.org/r/20210814211713.180533-5-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Alexander Lobakin <alobakin@pm.me> (mips)
Reviewed-by: Alexander Lobakin <alobakin@pm.me> (mips)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arc/Kconfig     |    1 -
 arch/arm64/Kconfig   |    1 -
 arch/mips/Kconfig    |    1 -
 arch/s390/Kconfig    |    1 -
 arch/x86/Kconfig     |    1 -
 arch/x86/um/Kconfig  |    1 -
 include/linux/find.h |   13 -------------
 lib/Kconfig          |    3 ---
 8 files changed, 22 deletions(-)
diff mbox series

Patch

--- a/arch/arc/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/arc/Kconfig
@@ -20,7 +20,6 @@  config ARC
 	select COMMON_CLK
 	select DMA_DIRECT_REMAP
 	select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)
-	select GENERIC_FIND_FIRST_BIT
 	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
--- a/arch/arm64/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/arm64/Kconfig
@@ -119,7 +119,6 @@  config ARM64
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
-	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IRQ_IPI
 	select GENERIC_IRQ_PROBE
--- a/arch/mips/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/mips/Kconfig
@@ -30,7 +30,6 @@  config MIPS
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_CPU_AUTOPROBE
-	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_IOMAP
 	select GENERIC_IRQ_PROBE
--- a/arch/s390/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/s390/Kconfig
@@ -126,7 +126,6 @@  config S390
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_ENTRY
-	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_PTDUMP
 	select GENERIC_SMP_IDLE_THREAD
--- a/arch/x86/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/x86/Kconfig
@@ -133,7 +133,6 @@  config X86
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_ENTRY
-	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_IOMAP
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
 	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
--- a/arch/x86/um/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/arch/x86/um/Kconfig
@@ -8,7 +8,6 @@  endmenu
 
 config UML_X86
 	def_bool y
-	select GENERIC_FIND_FIRST_BIT
 
 config 64BIT
 	bool "64-bit kernel" if "$(SUBARCH)" = "x86"
--- a/include/linux/find.h~arch-remove-generic_find_first_bit-entirely
+++ a/include/linux/find.h
@@ -101,8 +101,6 @@  unsigned long find_next_zero_bit(const u
 }
 #endif
 
-#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
-
 #ifndef find_first_bit
 /**
  * find_first_bit - find the first set bit in a memory region
@@ -147,17 +145,6 @@  unsigned long find_first_zero_bit(const
 }
 #endif
 
-#else /* CONFIG_GENERIC_FIND_FIRST_BIT */
-
-#ifndef find_first_bit
-#define find_first_bit(addr, size) find_next_bit((addr), (size), 0)
-#endif
-#ifndef find_first_zero_bit
-#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0)
-#endif
-
-#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
-
 #ifndef find_last_bit
 /**
  * find_last_bit - find the last set bit in a memory region
--- a/lib/Kconfig~arch-remove-generic_find_first_bit-entirely
+++ a/lib/Kconfig
@@ -59,9 +59,6 @@  config GENERIC_STRNLEN_USER
 config GENERIC_NET_UTILS
 	bool
 
-config GENERIC_FIND_FIRST_BIT
-	bool
-
 source "lib/math/Kconfig"
 
 config NO_GENERIC_PCI_IOPORT_MAP