On Mon, Nov 26, 2012 at 01:49:57PM -0800, Andrei Warkentin wrote: > Hi NFSD developers, > > I've found what I think is an interesting problem that occurs on single-CPU machines as far as I can tell. > > Basically the following snippet will occasionally loop forever printing that one thread is still running. Further > attempts to run "/usr/sbin/rpc.nfsd 0" don't help. > > /usr/sbin/rpc.nfsd 1 > /usr/sbin/rpc.nfsd 0 > while [ ! $[`cat /proc/fs/nfsd/threads`] -eq 0 ]; do > echo $[`cat /proc/fs/nfsd/threads`] still running > sleep .1 > done > > I've not looked a whole lot at it. It appears that although the paths calling svc_set_num_threads synchronize on nfsd_mutex, the code doesn't seem to try waiting on the number of threads to reach the desired count. Yeah, I guess it just signals and returns, I agree that's not ideal. Though in your case fixing that may just mean the "rpc.nfsd 0" would hang. > What do you guys think? That is odd. I'm not sure to suggest without spending a bunch of time on it. Presumably ps will still show an nfsd thread running? Might be interesting to see its stack (cat /proc/<pid>/stack) or look at a full sysrq-t dump (sysrq-t, then check the logs). Is it stuck spinning in some kind of loop? (E.g. does "top" show anything interesting?) If none of that provides any hints, I dunno, my caveman approach would be to just stare really hard and the relevant code and start sprinkling printk's around as necessary. --b. > > Thanks. > > A > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
