[PATCH] riscv: use the generic string routines
Palmer Dabbelt
palmer at dabbelt.com
Fri Sep 10 20:49:02 PDT 2021
On Thu, 05 Aug 2021 03:31:04 PDT (-0700), mcroce at linux.microsoft.com wrote:
> On Wed, Aug 4, 2021 at 10:40 PM Palmer Dabbelt <palmer at dabbelt.com> wrote:
>>
>> On Tue, 03 Aug 2021 09:54:34 PDT (-0700), mcroce at linux.microsoft.com wrote:
>> > On Mon, Jul 19, 2021 at 1:44 PM Matteo Croce <mcroce at linux.microsoft.com> wrote:
>> >>
>> >> From: Matteo Croce <mcroce at microsoft.com>
>> >>
>> >> Use the generic routines which handle alignment properly.
>> >>
>> >> These are the performances measured on a BeagleV machine for a
>> >> 32 mbyte buffer:
>> >>
>> >> memcpy:
>> >> original aligned: 75 Mb/s
>> >> original unaligned: 75 Mb/s
>> >> new aligned: 114 Mb/s
>> >> new unaligned: 107 Mb/s
>> >>
>> >> memset:
>> >> original aligned: 140 Mb/s
>> >> original unaligned: 140 Mb/s
>> >> new aligned: 241 Mb/s
>> >> new unaligned: 241 Mb/s
>> >>
>> >> TCP throughput with iperf3 gives a similar improvement as well.
>> >>
>> >> This is the binary size increase according to bloat-o-meter:
>> >>
>> >> add/remove: 0/0 grow/shrink: 4/2 up/down: 432/-36 (396)
>> >> Function old new delta
>> >> memcpy 36 324 +288
>> >> memset 32 148 +116
>> >> strlcpy 116 132 +16
>> >> strscpy_pad 84 96 +12
>> >> strlcat 176 164 -12
>> >> memmove 76 52 -24
>> >> Total: Before=1225371, After=1225767, chg +0.03%
>> >>
>> >> Signed-off-by: Matteo Croce <mcroce at microsoft.com>
>> >> Signed-off-by: Emil Renner Berthing <kernel at esmil.dk>
>> >> ---
>> >
>> > Hi,
>> >
>> > can someone have a look at this change and share opinions?
>>
>> This LGTM. How are the generic string routines landing? I'm happy to
>> take this into my for-next, but IIUC we need the optimized generic
>> versions first so we don't have a performance regression falling back to
>> the trivial ones for a bit. Is there a shared tag I can pull in?
>
> Hi,
>
> I see them only in linux-next by now.
These ended up getting rejected by Linus, so I'm going to hold off on
this for now. If they're really out of lib/ then I'll take the C
routines in arch/riscv, but either way it's an issue for the next
release.
More information about the linux-riscv
mailing list