Messages in this thread | | | Subject | Re: [PATCH] riscv: enable GENERIC_FIND_FIRST_BIT | From | Kefeng Wang <> | Date | Thu, 9 Sep 2021 08:58:31 +0800 |
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On 2021/9/8 23:04, Jisheng Zhang wrote: > Hi Palmer, > > On Sun, 18 Jul 2021 00:14:23 +0800 > Jisheng Zhang wrote: > >> From: Jisheng Zhang <jszhang@kernel.org> >> >> riscv doesn't implement architecture-optimized bitsearching functions >> such as find_first_{zero}_bit() etc. >> >> When GENERIC_FIND_FIRST_BIT=n, find_first_bit() is implemented with >> find_next_bit() which is less efficient. Enable GENERIC_FIND_FIRST_BIT >> for riscv to get more optimized find_first_bit() implementation, an >> initial test(lib/find_bit_benchmark) shows find_first_bit() performance >> is improved by nearly 32%. > It seems this patch is missed. Is it possible to pick it up for 2nd 5.15-rc1 PR? > > Thanks
It is enabled unconditionally by following commit
commit dbbccfe505ef8fae804677abf0564c1e07479102
Author: Yury Norov <yury.norov@gmail.com> Date: Tue Aug 24 09:59:56 2021 +1000
arch: remove GENERIC_FIND_FIRST_BIT entirely
> >> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> >> --- >> arch/riscv/Kconfig | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> index 8fcceb8eda07..7ebc54c5c245 100644 >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -47,6 +47,7 @@ config RISCV >> select GENERIC_ATOMIC64 if !64BIT >> select GENERIC_CLOCKEVENTS_BROADCAST if SMP >> select GENERIC_EARLY_IOREMAP >> + select GENERIC_FIND_FIRST_BIT >> select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO >> select GENERIC_IOREMAP >> select GENERIC_IRQ_MULTI_HANDLER > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv > . >
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