On Mon, Jun 07, 2021 at 06:39:38PM +0300, Andy Shevchenko wrote: > On Mon, May 10, 2021 at 04:34:21PM -0700, Yury Norov wrote: > > In the 5.12 cycle we enabled the 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@xxxxxxxxx/ > > > > I think it's time to make all architectures use find_{first,last}_bit() > > unconditionally and remove the corresponding config option. > > > > This patch doesn't introduce functional changes for arc, arm64, mips, > > s390 and x86 because they already enable GENERIC_FIND_FIRST_BIT. There > > will be no changes for arm because it implements find_{first,last}_bit > > in arch code. For other architectures I expect improvement both in > > performance and .text size. > > Subject like s/all:/arch:/. Ok, thanks. I will resend shortly as part of series, to fix m68k issue. > > It would be great if people with an access to real hardware would share > > the output of bloat-o-meter and lib/find_bit_benchmark. > > This is rather comment (should be below cutter '---' line). > > Anyway, seems good to my by the code: > Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > > Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx> > > --- > > 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/asm-generic/bitops/find.h | 12 ------------ > > lib/Kconfig | 3 --- > > 8 files changed, 21 deletions(-) > > > > diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig > > index bc8d6aecfbbd..9c991ba50db3 100644 > > --- a/arch/arc/Kconfig > > +++ b/arch/arc/Kconfig > > @@ -19,7 +19,6 @@ 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 > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index e09a9591af45..9d5b36f7d981 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -108,7 +108,6 @@ 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 > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > > index b72458215d20..3ddae7918386 100644 > > --- a/arch/mips/Kconfig > > +++ b/arch/mips/Kconfig > > @@ -27,7 +27,6 @@ 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 > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > > index c1ff874e6c2e..3a10ceb8a097 100644 > > --- a/arch/s390/Kconfig > > +++ b/arch/s390/Kconfig > > @@ -125,7 +125,6 @@ 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 > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > index b83364a15d34..6a7d8305365e 100644 > > --- a/arch/x86/Kconfig > > +++ b/arch/x86/Kconfig > > @@ -123,7 +123,6 @@ 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 > > diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig > > index 95d26a69088b..40d6a06e41c8 100644 > > --- a/arch/x86/um/Kconfig > > +++ b/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" > > diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h > > index 0d132ee2a291..8a7b70c79e15 100644 > > --- a/include/asm-generic/bitops/find.h > > +++ b/include/asm-generic/bitops/find.h > > @@ -95,8 +95,6 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, > > } > > #endif > > > > -#ifdef CONFIG_GENERIC_FIND_FIRST_BIT > > - > > /** > > * find_first_bit - find the first set bit in a memory region > > * @addr: The address to start the search at > > @@ -136,16 +134,6 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) > > > > return _find_first_zero_bit(addr, size); > > } > > -#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 > > /** > > diff --git a/lib/Kconfig b/lib/Kconfig > > index a38cc61256f1..8346b3181214 100644 > > --- a/lib/Kconfig > > +++ b/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 > > -- > > 2.25.1 > > > > -- > With Best Regards, > Andy Shevchenko >
