Indeed. And even though glibc has only recently introduced support for rseq, the rseq system call has been around for a while. Search around, I found tcmalloc

Indeed. And even though glibc has only recently introduced support for rseq, the rseq system call has been around for a while. Search around, I found tcmalloc (https://google.github.io/tcmalloc/ https://google.github.io/tcmalloc/) is an example of software that is using rseq today, without glibc's support. And as far as I can tell, tcmalloc is using rseq both with a 'per-CPU' structure (actually portions of a larger block of memory), and without a requirement to pin processes or threads to a particular CPU. Their design document (https://google.github.io/tcmalloc/rseq.html https://google.github.io/tcmalloc/rseq.html) might be of interest to you.