On Fri, Nov 2, 2018 at 4:53 AM Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote: > > Here is a third round of prototype registering rseq(2) TLS for each > thread (including main), and unregistering for each thread (excluding > main). "rseq" stands for Restartable Sequences. > > Remaining open questions: > > - How early do we want to register rseq and how late do we want to > unregister it ? It's important to consider if we expect rseq to > be used by the memory allocator and within destructor callbacks. > However, we want to be sure the TLS (__thread) area is properly > allocated across its entire use by rseq. > > - We do not need an atomic increment/decrement for the refcount per > se. Just being atomic with respect to the current thread (and nested > signals) would be enough. What is the proper API to use there ? > > See the rseq(2) man page proposed here: > https://lkml.org/lkml/2018/9/19/647 > Merely having rseq registered carries some small but nonzero overhead, right? Should this perhaps live in a librseq.so or similar (possibly built as part of libc) to avoid the overhead for programs that don't use it?
