On Thu, 2010-11-04 at 20:26 +0100, Richard Cochran wrote: > The clock_ syscalls are moved into a new file and they call the older > posix functions when needed. The timer_ syscalls stay where they are, > in posix-timers.c, since I did not want to change the fairly involved > timer management code. Eventually, we could remove the posix clock_* > functions for the CLOCK_* ids from posix-timers.c and rework them > using the new dynamic clock api. That would leave just the timer code > in posix-timers.c, as the file name suggests. > > I dropped the idea of having user space open a sysfs file in order to > get a reference to a clock, since there are no open/release hooks > within sysfs for drivers (coincidentally, there has been some talk > about this on the lkml recently, but previously Greg KH object to > abusing sysfs as a "clockfs"). > > Instead, since many clocks (hpet, rtc, ptp, ...) will want to offer a > custom chardev for special advanced functionality, the dynamic clock > layer registers a cdev for the driver, placing its own hooks into the > open/release methods. The driver thus needs to access its private data > via a standard access method (not just by using fp->private_data). If > a driver doesn't want any chardev functions, that is okay, too. > > Well, please take a look and let me know what you think. Hey Richard! Thanks for sending this patchset out for review! This is definitely a larger redesign from your earlier patch, and I see now how the per-thread cputime clockids throws a wrench in my argument just using the incremental clockids that hash into a smaller array to avoid id reuse. That said, given how different this is from the last implementation, I'm not fully clear I see how to integrate this into my patch set. It might be useful to see a trivial example of how you see a clockdevice being registered and used. Overall it looks interesting, but there may be a few catches that we may have to watch out for. I have a few other comments I'll make in context of the patches to follow shortly. thanks again! -john -- 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