----- On Jul 3, 2018, at 2:11 PM, Peter Zijlstra peterz@xxxxxxxxxxxxx wrote: > On Tue, Jul 03, 2018 at 01:58:37PM -0400, Mathieu Desnoyers wrote: >> I can modify the ABI to put the cpu_id_start and cpu_id fields inside >> a union, and update it with a single store. >> >> Thoughts ? > > Let's keep them for now, we can always frob this later, they are aligned > and proper, no need to expose that union to userspace. Isn't it weird to change the API of an exposed public uapi header ? What if userspace chooses to do sizeof(__rseq_abi.cpu_id) ? We would break this unless we use a transparent union, which puts constraints I would hope not to have on compilers supporting transparent unions (I recall C++ had issues with this). I'd prefer to expose the union right away if it's fine with you. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
