Re: [PATCH 2/2] MIPS: enable GENERIC_FIND_FIRST_BIT
From: Huacai Chen <chenhuacai@kernel.org>
Date: 2021-02-26 01:24:05
Also in:
linux-arm-kernel, linux-mips, lkml
Hi, Yury, On Thu, Feb 25, 2021 at 9:59 PM Yury Norov [off-list ref] wrote:
From: Alexander Lobakin <redacted>
MIPS doesn't have architecture-optimized bitsearching functions,
like find_{first,next}_bit() etc.Emm, I think MIPS can use clo/clz to optimize bitsearching functions. Huacai
quoted hunk ↗ jump to hunk
It's absolutely harmless to enable GENERIC_FIND_FIRST_BIT as this functionality is not new at all and well-tested. It provides more optimized code and saves some .text memory (32 R2): add/remove: 4/1 grow/shrink: 1/53 up/down: 216/-372 (-156) Users of for_each_set_bit() like hotpath gic_handle_shared_int() will also benefit from this. Suggested-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Alexander Lobakin <redacted> Signed-off-by: Yury Norov <yury.norov@gmail.com> --- arch/mips/Kconfig | 1 + 1 file changed, 1 insertion(+)diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index d89efba3d8a4..164bdd715d4b 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig@@ -26,6 +26,7 @@ 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 --2.25.1