Re: [PATCH v4] arm64: lib: accelerate do_csum

[Shaokun Zhang <zhangshaokun@hisilicon.com>]

+Cc Yuke Zhang who has used this patch and enjoyed the patch's gain when debugged
the performance issue.

Hi Will,

Thanks for reactivate this thread.
Robin, any comments are welcome and hopefully it can be merged in mainline.

Thanks,
Shaokun

On 2020/1/9 1:20, Will Deacon wrote:
> On Wed, Nov 06, 2019 at 10:20:06AM +0800, Shaokun Zhang wrote:
>> From: Lingyan Huang <huanglingyan2@huawei.com>
>>
>> Function do_csum() in lib/checksum.c is used to compute checksum,
>> which is turned out to be slowly and costs a lot of resources.
>> Let's accelerate the checksum computation for arm64.
>>
>> While we test its performance on Huawei Kunpeng 920 SoC, as follow:
>>  1cycle  general(ns)  csum_128(ns) csum_64(ns)
>>   64B:        160            80             50
>>  256B:        120            70             60
>> 1023B:        350           140            150
>> 1024B:        350           130            140
>> 1500B:        470           170            180
>> 2048B:        630           210            240
>> 4095B:       1220           390            430
>> 4096B:       1230           390            430
>>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Robin Murphy <robin.murphy@arm.com>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Originally-from: Robin Murphy <robin.murphy@arm.com>
>> Signed-off-by: Lingyan Huang <huanglingyan2@huawei.com>
>> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
>> ---
>> Hi,                                                                
>> Apologies that we post this version so later, because we want to   
>> optimise it better, Lingyan tested it performance which is attached
>> in commit log. Both(128 and 64) are much better than the initial   
>> code.                                                              
>> ChangeLog:
>>     based on Robin's code and change strides from 64 to 128.
>>
>>  arch/arm64/include/asm/checksum.h |  3 ++
>>  arch/arm64/lib/Makefile           |  2 +-
>>  arch/arm64/lib/csum.c             | 81 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 85 insertions(+), 1 deletion(-)
>>  create mode 100644 arch/arm64/lib/csum.c
> 
> Robin -- any chance you could look at this please? If it's based on your
> code then hopefully it's straightforward to review ;)
> 
> Will
> 
> .
> 


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel