Re: CPU affinity behavior of liburcu call-rcu per-cpu worker threads

[Mathieu Desnoyers via lttng-dev <lttng-dev@lists.lttng.org>]

On 2026-07-09 22:53, Paul E. McKenney wrote:
[...]
> 
>> And unfortunately, for me, tcmalloc is really not a viable option,
>> because it needs to own the RSEQ area registration, and because glibc
>> cannot use it at the same time as tcmalloc, my benchmarks suffer because
>> glibc has a slower sched_getcpu() implementation.
>>
>> So jemalloc it is. tcmalloc is not usable for me because they don't
>> compose with the rest of the world. I warned the tcmalloc developers
>> many times, but they did not listen. :-(
> 
> So an alternative rseq for the rest of us?

I'm not quite sure I understand. Since there is only one rseq
registration per thread, this means that tcmalloc require their
users to use a GLIBC tunable to disable rseq registration at the
libc level, leaving rseq solely to tcmalloc.

Thanks,

Mathieu


-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com