[PATCH] Add support cache line size for Hygon Dhyana CPU

[Jinke Fan]

Hello Maxim,

On 2019/5/9 0:10, Maxim Dounin wrote:
> Hello!
> 
> On Tue, May 07, 2019 at 07:25:59AM +0000, Jinke Fan wrote:
> 
>> # HG changeset patch
>> # User Fanjinke <fanjinke at hygon.cn>
>> # Date 1557209225 -28800
>> #      Tue May 07 14:07:05 2019 +0800
>> # Node ID 9bc6da16b217ce2c5fc63048a705c2b3195d3bb7
>> # Parent  16a1adadf43751f59257ba419f6bacd530dd19d3
>> Add support cache line size for Hygon Dhyana CPU
>>
>> Background:
>> Chengdu Haiguang IC Design Co., Ltd (Hygon) is a Joint Venture between
>> AMD and Haiguang Information Technology Co.,Ltd., aims at providing high
>> performance x86 processor for China server market. Its first generation
>> processor codename is Dhyana, which originates from AMD technology and
>> shares most of the architecture with AMD's family 17h, but with different
>> CPU Vendor ID("HygonGenuine")/Family series number(Family 18h).
>>
>> diff -r 16a1adadf437 -r 9bc6da16b217 src/core/ngx_cpuinfo.c
>> --- a/src/core/ngx_cpuinfo.c	Wed Apr 24 16:38:56 2019 +0300
>> +++ b/src/core/ngx_cpuinfo.c	Tue May 07 14:07:05 2019 +0800
>> @@ -124,6 +124,8 @@
>>
>>         } else if (ngx_strcmp(vendor, "AuthenticAMD") == 0) {
>>             ngx_cacheline_size = 64;
>> +    } else if (ngx_strcmp(vendor, "HygonGenuine") == 0) {
>> +        ngx_cacheline_size = 64;
>>         }
>>     }
>>
> 
> Thank you for the patch.
> 
> Starting with nginx 1.13.8 this should already work out of the box
> on systems with sysconf(_SC_LEVEL1_DCACHE_LINESIZE) - that is, at
> least on all Linux systems - as long as the processor is supported
> by OS.  Also, the default is 64 anyway on 64-bit platforms.
> 

Thank you so much for viewing the patch.

sysconf(_SC_LEVEL1_DCACHE_LINESIZE) support Hygon CPU since glibc-2.29,
so,before glibc-2.29 sysconf(_SC_LEVEL1_DCACHE_LINESIZE) will return
zero.

ngx_cacheline_size = NGX_CPU_CACHE_LINE;

Yes, actually, the NGX_CPU_CACHE_LINE is 64 on Hygon platform .

Best Regards!
Jinke.