It seems that building against glibc 2.12 is still supported. Is this something that is still needed?
I'm mostly concerned with this fallback code on x86-64: // Unfortunately we have to bring all these macros here from vsyscall.h // to be able to compile on old linuxes. #define __NR_vgetcpu 2 #define VSYSCALL_START (-10UL << 20) #define VSYSCALL_SIZE 1024 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); retval = vgetcpu(&cpu, NULL, NULL); There is no way to check that the kernel actually supports vsyscall, and on some kernels, this will crash because they have disabled vsyscall. I would like to remove this or switch over to the system call (as already used on i386). This is fallback code only, so performance does not really matter: on newer glibc (starting with 2.14), sched_getcpu will be found, and it will use vDSO or rseq as appropriate. Thanks, Florian
