On Tuesday November 6, akpm@xxxxxxxxxxxxxxxxxxxx wrote: > > On Tue, 6 Nov 2007 14:28:11 +0300 Al Boldi <a1426z@xxxxxxxxx> wrote: > > Al Boldi wrote: > > > There is a massive (3-18x) slowdown when re-querying a large nfs dir (2k+ > > > entries) using a simple ls -l. > > > > > > On 2.6.23 client and server running userland rpc.nfs.V2: > > > first try: time -p ls -l <2k+ entry dir> in ~2.5sec > > > more tries: time -p ls -l <2k+ entry dir> in ~8sec > > > > > > first try: time -p ls -l <5k+ entry dir> in ~9sec > > > more tries: time -p ls -l <5k+ entry dir> in ~180sec > > > > > > On 2.6.23 client and 2.4.31 server running userland rpc.nfs.V2: > > > first try: time -p ls -l <2k+ entry dir> in ~2.5sec > > > more tries: time -p ls -l <2k+ entry dir> in ~7sec > > > > > > first try: time -p ls -l <5k+ entry dir> in ~8sec > > > more tries: time -p ls -l <5k+ entry dir> in ~43sec > > > > > > Remounting the nfs-dir on the client resets the problem. > > > > > > Any ideas? > > > > Ok, I played some more with this, and it turns out that nfsV3 is a lot > > faster. But, this does not explain why the 2.4.31 kernel is still over > > 4-times faster than 2.6.23. > > > > Can anybody explain what's going on? > > > > Sure, Neil can! ;) Nuh. He said "userland rpc.nfs.Vx". I only do "kernel-land NFS". In these days of high specialisation, each line of code is owned by a different person, and finding the right person is hard.... I would suggest getting a 'tcpdump -s0' trace and seeing (with wireshark) what is different between the various cases. NeilBrown - 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
