need help for avoiding system calls while using URCU (Userspace RCU)

[方锴]

dear kienan<br/>Thank you for your guidance, I've found DKDP's URCU successfully avoids system calls. Grateful for your support!<br/>Best regards,<br/>fangkai
At 2025-03-07 00:17:34, "Kienan Stewart" <kstewart at efficios.com> wrote:
>Hi 方锴,
>
>On 3/4/25 3:09 AM, 方锴 via lttng-dev wrote:
>
>> I have referenced your project, URCU (Userspace RCU), on GitHub, which is based on the QSBR model. However, I 
>noticed that when using it in user mode, it makes system calls to enter 
>the kernel. Could you please provide guidance on how to address this issue?
>
>Are there specific parts of the API that you need to be user-space only?
>
> > I aim to achieve a pure user-mode implementation. Specifically, I 
>would appreciate any insights or suggestions on avoiding system calls 
>while still maintaining the functionality of the QSBR model in user 
>space. Thank you very much for your time and assistance.
>
>Currently the locking is done using futexs, which are system calls. 
>Those could potentially be replaced with a poll/retry system either in a 
>different flavour of URCU or at build-time.
>
>thanks,
>kienan