Re: [PATCH] fix linux kernel BTF builds: increase max percpu variables by 10x

[Alan Maguire <alan.maguire@oracle.com>]

On 28/02/2024 23:21, John Hubbard wrote:
> On 2/28/24 04:04, Alan Maguire wrote:
>> On 28/02/2024 09:20, Jiri Olsa wrote:
>>> On Tue, Feb 27, 2024 at 07:21:42PM -0800, John Hubbard wrote:
> ...
>>> do you have an actual count of percpu variables for your config?
> 
> That's a very reasonable question...
> 
>>> 10x seems a lot to me
> 
> Me too. This was a "make the problem go away now please" type of "fix". :)
> 


Running

bpftool btf dump file vmlinux |grep "] VAR"

...should give us a sense of what's going on. I only see 375 per-cpu
variables when I do this so maybe there's something
kernel-config-specific that might explain why you have so many more?

>>>
>>> this might be a workaround, but we should make encoder->percpu.vars
>>> dynamically allocated like we do for functions
> 
> Yes, that's a much better design imho.
> 
>>>
>>> jirka
>>>
>>
>> Good idea Jiri; John would you mind trying the attached patch? Thanks!
> 
> It works perfectly for me. For that patch, please feel free to add:
> 
> Tested-by: John Hubbard <jhubbard@nvidia.com>
>


that's great, thanks for testing this John!

Alan

> 
> thanks,