On Thu, Mar 26, 2015 at 11:47:03AM -0400, Anna Schumaker wrote: > On 03/26/2015 11:38 AM, J. Bruce Fields wrote: > > On Thu, Mar 26, 2015 at 11:32:25AM -0400, Trond Myklebust wrote: > >> On Thu, Mar 26, 2015 at 11:21 AM, Anna Schumaker > >> <Anna.Schumaker@xxxxxxxxxx> wrote: > >>> Here are my updated numbers! I tested with files 5G in size: one 100% data, one 100% hole, and one alternating between hole and data every 4K. I collected data for both v4.1 and v4.2 with and without the READ_PLUS patches: > >>> > >>> ########################## > >>> # # > >>> # Without READ_PLUS # > >>> # # > >>> ########################## > >>> > >>> > >>> NFS v4.1: > >>> Trial > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | | 1 | 2 | 3 | 4 | 5 | Average | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | Data | 8.723s | 7.243s | 8.252s | 6.997s | 6.980s | 7.639s | > >>> | Hole | 5.271s | 5.224s | 5.060s | 4.897s | 5.321s | 5.155s | > >>> | Mixed | 8.050s | 10.057s | 7.919s | 8.060s | 9.557s | 8.729s | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> > >>> > >>> > >>> > >>> NFS v4.2: > >>> Trial > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | | 1 | 2 | 3 | 4 | 5 | Average | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | Data | 6.707s | 7.070s | 6.722s | 6.761s | 6.810s | 6.814s | > >>> | Hole | 5.152s | 5.149s | 5.213s | 5.206s | 5.312s | 5.206s | > >>> | Mixed | 7.979s | 7.985s | 8.177s | 7.772s | 8.280s | 8.039s | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> > >>> > >>> > >>> > >>> > >>> ####################### > >>> # # > >>> # With READ_PLUS # > >>> # # > >>> ####################### > >>> > >>> > >>> NFS v4.1: > >>> Trial > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | | 1 | 2 | 3 | 4 | 5 | Average | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | Data | 9.082s | 7.008s | 7.116s | 6.771s | 7.902s | 7.576s | > >>> | Hole | 5.333s | 5.358s | 5.380s | 5.161s | 5.282s | 5.303s | > >>> | Mixed | 8.189s | 8.308s | 9.540s | 7.937s | 8.420s | 8.479s | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> > >>> > >>> > >>> > >>> NFS v4.2: > >>> Trial > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | | 1 | 2 | 3 | 4 | 5 | Average | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> | Data | 7.033s | 6.829s | 7.025s | 6.873s | 7.134s | 6.979s | > >>> | Hole | 1.794s | 1.800s | 1.905s | 1.811s | 1.725s | 1.807s | > >>> | Mixed | 7.590s | 8.777s | 9.423s | 10.366s | 8.024s | 8.836s | > >>> |---------|---------|---------|---------|---------|---------|---------| > >>> > >> > >> So there is a clear win in the 100% hole case here, but otherwise the > >> statistical fluctuations are dominating the numbers. Can you get us a > >> little more stats and then perhaps run the results through nfsometer? > > > > Also, could you describe the setup (are these still kvm's), and how > > you're clearing the cache between runs? > > These are still KVMs and my server is exporting an xfs filesystem. I clear caches by running "echo 3 > /proc/sys/vm/drop_caches" on the server before every read, and I remount my client after reading each set of three files once. What sort of device is the exported xfs filesystem on? (Can't there be a second level of caching on the guest, depending on how it's set up?) Can we get results on bare metal? (The kvm test might be a good worst-case for read_plus, as I'd expect bandwidth to be relatively high compared to the cost of the extra memcpy's or seek calls. But it also seems more complicated.) --b. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
