> On Thu, 8 Nov 2007 10:44:35 +0300 Al Boldi <a1426z@xxxxxxxxx> wrote: > Andrew Morton wrote: > > > > I would suggest getting a 'tcpdump -s0' trace and seeing (with > > > > wireshark) what is different between the various cases. > > > > > > Thanks Neil for looking into this. Your suggestion has already been > > > answered in a previous post, where the difference has been attributed to > > > "ls -l" inducing lookup for the first try, which is fast, and getattr > > > for later tries, which is super-slow. > > > > > > Now it's easy to blame the userland rpc.nfs.V2 server for this, but > > > what's not clear is how come 2.4.31 handles getattr faster than 2.6.23? > > > > We broke 2.6? It'd be interesting to run the ls in an infinite loop on > > the client them start poking at the server. Is the 2.6 server doing > > physical IO? Is the 2.6 server consuming more system time? etc. A basic > > `vmstat 1' trace for both 2.4 and 2.6 would be a starting point. > > > > Could be that there's some additional latency caused by networking > > changes, too. I expect the tcpdump/wireshark/etc traces would have > > sufficient resolution for us to be able to see that. > > The problem turns out to be "tune2fs -O dir_index". > Removing that feature resolves the big slowdown. Doh. Well worked-out. > Does 2.4.31 support this feature? No. This explains it. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
