On Mon, Nov 21, 2011 at 12:54 AM, Max Filippov <jcmvb...@gmail.com> wrote: > Add check for the EFD_NONBLOCK and EFD_CLOEXEC flags to the > CONFIG_EVENTFD test. > This fixes the following build failure on Fedora 9: > > CC event_notifier.o > event_notifier.c: In function `event_notifier_init': > event_notifier.c:21: error: `EFD_NONBLOCK' undeclared (first use in this > function) > event_notifier.c:21: error: (Each undeclared identifier is reported only > once > event_notifier.c:21: error: for each function it appears in.) > event_notifier.c:21: error: `EFD_CLOEXEC' undeclared (first use in this > function) > make: *** [event_notifier.o] Error 1 > > Signed-off-by: Max Filippov <jcmvb...@gmail.com> > --- > configure | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-)
Reviewed-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com> At first this patch seemed suspicious because is undefines CONFIG_EVENTFD on hosts that previously had it defined. A graceful fallback that sets nonblocking and close-on-exec using fcntl(2) is possible, so we don't *need* to be as aggressive as this patch. However, I chased up the dependencies and it doesn't seem worth doing. CONFIG_EVENTFD is a dependency for vhost-net, aio=native, and has fallbacks elsewhere in QEMU. Given that vhost-net was merged in 2.6.34 and the eventfd open flags were introduced in 2.6.27, I think the only feature we actually risk losing here is Linux AIO (aio=native). 2.6.27-based kernels are old so I'm happy with this change. Stefan
