On Wed, Aug 04, 2010 at 06:46:38PM +0300, Alexander Shishkin wrote: > On Wed, Aug 04, 2010 at 06:32:21 +0300, Kirill A. Shutemov wrote: > > On Wed, Aug 04, 2010 at 03:48:28PM +0300, Alexander Shishkin wrote: > > > Certain userspace applications (like "clock" desktop applets or ntpd) > > > might > > > want to be notified when some other application changes the system time. > > > It > > > might also be important for an application to be able to distinguish > > > between > > > its own and somebody else's time changes. > > > > > > This patch implements a notification interface via eventfd mechanism. > > > Proccess > > > wishing to be notified about time changes should create an eventfd and > > > echo > > > its file descriptor to /sys/kernel/time_notify. After that, any calls to > > > settimeofday()/stime()/adjtimex() made by other processes will be > > > signalled > > > to this eventfd. Credits for suggesting the eventfd mechanism for this > > > purpose go te Kirill Shutemov. > > > > > > So far, this implementation can only filter out notifications caused by > > > time change calls made by the process that wrote the eventfd descriptor to > > > sysfs, but not its children which (might) have inherited the eventfd. It > > > is so far not clear to me whether this is bad and more confusing than > > > excluding such children as well. > > > > I think it's a bad idea to filter notifications. Let's leave it for > > Why?
Someone might want to recieve notifications about its own activity. It's a policy. Kernel should provide mechanism, not policy. -- Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
