Hi, As RFC (still), the new Restartable sequence tree tag <v4.14-rseq-20171113> can be found at: https://git.kernel.org/pub/scm/linux/kernel/git/rseq/linux-rseq.git/ It includes the new rseq and cpu_opv system calls implemented on x86 32/64, powerpc 32/64, and arm 32. It also includes the following improvements to the membarrier system call: * new expedited membarrier command and registration command for shared mappings: all architectures implementing membarrier. * new core serializing membarrier command and registration command for JITs (private mappings): x86 32/64, and arm 64. Regarding the membarrier helper for JIT, I'm still uneasy about sending it as a PR for this merge window, given that I have not received any user feedback on real-life JIT integration yet. I have moved those commits to the end of the patchset to they can be easily removed and delayed to 4.16 if needed. Orion Hodson at Google promised to try it out in the next few days. He has reproducers of JIT issues on ARM64, so I have ported this feature to arm64 to allow him to do some tests. Linus, this is _not_ the PR yet, but should be pretty close to its final form. I'm mainly waiting for feedback on from Orion Hodson before I decide whether to leave the core serializing membarrier commits in there, or delay them to 4.16. Feedback is welcome, Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
