* Paolo Bonzini (pbonz...@redhat.com) wrote: > > > On 30/03/2015 16:07, Dr. David Alan Gilbert wrote: > >>> > > > >> > > >> > You would just require new _installed_ kernel headers. Then you can use > >> > linux/userfaultfd.h and syscall.h (the latter from glibc, includes > >> > asm/unistd.h to get syscall numbers). > >> > > >> > linux-headers/ is useful for APIs that do not require system calls, or > >> > for APIs that are extensible. However, if a system call is required > >> > (and mandatory) it's simpler to just use installed headers. > > OK, so then I could check for ifdef __NR_userfault and then > > do the include and I think that would be safe. > > I think it's okay. First include syscall.h, then include > linux/userfaultfd.h under #ifdef. > > > Although then what's the best way to tell people to try it out > > without an updated libc? > > They don't need an updated libc, just an updated kernel. syscall.h is > just a wrapper around Linux headers.
That's what I've implemented in the v6 and the v7 I've just posted. Dave > > Paolo > > > Or is it best to modify ./configure to detect it? -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
