| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <YMD566T1cGfy7DJA@yury-ThinkPad>
Date: Wed, 9 Jun 2021 10:27:07 -0700
From: Yury Norov <yury.norov@...il.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
Alexander Lobakin <alobakin@...me>,
Alexey Klimov <aklimov@...hat.com>,
Anton Ivanov <anton.ivanov@...bridgegreys.com>,
Arnd Bergmann <arnd@...db.de>, Borislav Petkov <bp@...en8.de>,
Catalin Marinas <catalin.marinas@....com>,
Christian Borntraeger <borntraeger@...ibm.com>,
Dan Williams <dan.j.williams@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Ingo Molnar <mingo@...hat.com>,
Jacob Keller <jacob.e.keller@...el.com>,
Jarkko Sakkinen <jarkko@...nel.org>,
Jeff Dike <jdike@...toit.com>,
Kees Cook <keescook@...omium.org>,
Mark Brown <broonie@...nel.org>,
Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
Nick Terrell <terrelln@...com>,
Palmer Dabbelt <palmerdabbelt@...gle.com>,
Rasmus Villemoes <linux@...musvillemoes.dk>,
Richard Weinberger <richard@....at>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Thomas Gleixner <tglx@...utronix.de>,
Vasily Gorbik <gor@...ux.ibm.com>,
Vijayanand Jitta <vjitta@...eaurora.org>,
Vineet Gupta <vgupta@...opsys.com>,
Will Deacon <will@...nel.org>, Yogesh Lal <ylal@...eaurora.org>
Subject: Re: [PATCH] all: remove GENERIC_FIND_FIRST_BIT
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@gmail.com/
> >
> > 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@...ux.intel.com>
>
> > Signed-off-by: Yury Norov <yury.norov@...il.com>
> > ---
> > 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
>
Powered by blists - more mailing lists