Messages in this thread | | | Subject | Re: [patch 0/9] x86_64: reliable TSC-based gettimeofday | From | john stultz <> | Date | Thu, 01 Feb 2007 08:56:48 -0800 |
| |
On Thu, 2007-02-01 at 15:52 +0100, Jiri Bohac wrote: > On Thu, Feb 01, 2007 at 12:20:59PM +0100, Andi Kleen wrote: >> > > The big strategic problem is how to marry your patchkit to John Stultz's > > clocksources work which is also competing for merge. Any thoughts on that? > > I'll look into that next week. Sorry, I wanted to do that a long time > ago, but I spent weeks (over a month) fighting a nasty livelock > in the code. (Morale: think twice before using a spinlock inside > a {do .. while (read_seqretry(..))} loop)
The first step here shouldn't be too difficult. Just create a _read function that uses your code to return monotonic TSC cycles (instead of nanoseconds w/ gettimeofday). Then just create a clocksource structure for it.
The harder part will be the vsyscall, as you will need extra per cpu data in the vsyscall read. I had some test code for this situation awhile back, so if you get the first part functioning correctly (just a clocksource w/o a vread pointer), I'll gladly help you get the vsyscall bits working.
thanks -john
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |