[Pkg-nginx-maintainers] Bug#1140605: nginx: Cache line size on loong64 may be too small

[xiao sheng wen(肖盛文)]

I'm sorry for my last email, the "line break" is lost.

I use KDE, Thunderbird to send email, when I copy and paste the output from 
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But after I send out email, the "line break" is lost.

在 2026/6/24 14:24, xiao sheng wen(肖盛文) 写道:
> Hi,
>
> 在 2026/6/23 19:30, Colin Watson 写道:
>> Source: nginx
>> Version: 1.30.1-4
>> Severity: normal
>> X-Debbugs-Cc: debian-loongarch at lists.debian.org, debian-loongarch at lists.debian.org
>> User: debian-loongarch at lists.debian.org
>> Usertags: loong64
>>
>> I noticed that debusine's autopkgtests are failing on loong64 (e.g.  
>> https://ci.debian.net/packages/d/debusine/testing/loong64/72375884/).  
>> On investigation, I found this in its test artifacts:
>>
>>   Jun 22 10:47:53 ci-173-ef19176d nginx[8035]: 2026/06/22 10:47:53 [emerg] 8035#8035: could not build server_names_hash, you should increase server_names_hash_bucket_size: 32
>>   Jun 22 10:47:53 ci-173-ef19176d nginx[8035]: nginx: configuration file /etc/nginx/nginx.conf test failed
>>
>> I suppose we could work around this in debusine, as suggested in 
>> https://nginx.org/en/docs/http/server_names.html#optimization.  However, 
>> I think this message points to nginx being configured suboptimally on 
>> this architecture.  The default value of server_names_hash_bucket_size 
>> is set to nginx's idea of the CPU cache line size.  Looking at 
>> https://salsa.debian.org/nginx-team/nginx/-/blob/debian/latest/auto/os/conf, 
>> it seems that this is set based on matching the architecture name.  No 
>> specific value is set for the case where $NGX_MACHINE is loongarch64, so 
>> it falls back to 32.

Your investigation is appreciate!

>> I'm not an architecture expert, but looking at e.g. 
>> https://github.com/golang/go/blob/master/src/internal/cpu/cpu_loong64.go 
>> it seems as though 64 might be a better choice on this architecture.  
>> Could anyone on debian-loongarch@ confirm or contradict this?

Yes, 64 is a better choice on loong64 architecture.


The following is run on my test loong64 machine: 

root at klx:~# arch

loongarch64 

root at klx:~# uname -a

Linux klx 7.0.12+deb14-loong64 #1 SMP PREEMPT Debian 7.0.12-1 (2026-06-09) loongarch64 GNU/Linux 


root at klx:~# cat /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size

64

I also confirm this through the Chinese Wechat group with staff in loongson company.



Regards,

-- 
肖盛文 xiao sheng wen -- Debian Developer(atzlinux)
Debian QA page: https://qa.debian.org/developer.php?login=atzlinux%40debian.org
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