From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> These patches add server support for the READ_PLUS operation, which breaks read requests into several "data" and "hole" segments when replying to the client. Here are the results of some performance tests I ran on Netapp lab machines. I tested by reading various 2G files from a few different undelying filesystems and across several NFS versions. I used the `vmtouch` utility to make sure files were only cached when we wanted them to be. In addition to 100% data and 100% hole cases, I also tested with files that alternate between data and hole segments. These files have either 4K, 8K, 16K, or 32K segment sizes and start with either data or hole segments. So the file mixed-4d has a 4K segment size beginning with a data segment, but mixed-32h hase 32K segments beginning with a hole. The units are in seconds, with the first number for each NFS version being the uncached read time and the second number is for when the file is cached on the server. ext4 | v3 | v4.0 | v4.1 | v4.2 | ----------|-----------------|-----------------|-----------------|-----------------| data | 22.909 : 18.253 | 22.934 : 18.252 | 22.902 : 18.253 | 23.485 : 18.253 | hole | 18.256 : 18.253 | 18.255 : 18.252 | 18.256 : 18.253 | 0.708 : 0.709 | mixed-4d | 28.261 : 18.253 | 29.616 : 18.252 | 28.341 : 18.252 | 24.508 : 9.150 | mixed-8d | 27.956 : 18.253 | 28.404 : 18.252 | 28.320 : 18.252 | 23.967 : 9.140 | mixed-16d | 28.172 : 18.253 | 27.946 : 18.252 | 27.627 : 18.252 | 23.043 : 9.134 | mixed-32d | 25.350 : 18.253 | 24.406 : 18.252 | 24.384 : 18.253 | 20.698 : 9.132 | mixed-4h | 28.913 : 18.253 | 28.564 : 18.252 | 27.996 : 18.252 | 21.837 : 9.150 | mixed-8h | 28.625 : 18.253 | 27.833 : 18.252 | 27.798 : 18.253 | 21.710 : 9.140 | mixed-16h | 27.975 : 18.253 | 27.662 : 18.252 | 27.795 : 18.253 | 20.585 : 9.134 | mixed-32h | 25.958 : 18.253 | 25.491 : 18.252 | 24.856 : 18.252 | 21.018 : 9.132 | xfs | v3 | v4.0 | v4.1 | v4.2 | ----------|-----------------|-----------------|-----------------|-----------------| data | 22.041 : 18.253 | 22.618 : 18.252 | 23.067 : 18.253 | 23.496 : 18.253 | hole | 18.256 : 18.253 | 18.255 : 18.252 | 18.256 : 18.253 | 0.723 : 0.708 | mixed-4d | 29.417 : 18.253 | 28.503 : 18.252 | 28.671 : 18.253 | 24.957 : 9.150 | mixed-8d | 29.080 : 18.253 | 29.401 : 18.252 | 29.251 : 18.252 | 24.625 : 9.140 | mixed-16d | 27.638 : 18.253 | 28.606 : 18.252 | 27.871 : 18.253 | 25.511 : 9.135 | mixed-32d | 24.967 : 18.253 | 25.239 : 18.252 | 25.434 : 18.252 | 21.728 : 9.132 | mixed-4h | 34.816 : 18.253 | 36.243 : 18.252 | 35.837 : 18.252 | 32.332 : 9.150 | mixed-8h | 43.469 : 18.253 | 44.009 : 18.252 | 43.810 : 18.253 | 37.962 : 9.140 | mixed-16h | 29.280 : 18.253 | 28.563 : 18.252 | 28.241 : 18.252 | 22.116 : 9.134 | mixed-32h | 29.428 : 18.253 | 29.378 : 18.252 | 28.808 : 18.253 | 27.378 : 9.134 | btrfs | v3 | v4.0 | v4.1 | v4.2 | ----------|-----------------|-----------------|-----------------|-----------------| data | 25.547 : 18.253 | 25.053 : 18.252 | 24.209 : 18.253 | 32.121 : 18.253 | hole | 18.256 : 18.253 | 18.255 : 18.252 | 18.256 : 18.252 | 0.702 : 0.724 | mixed-4d | 19.016 : 18.253 | 18.822 : 18.252 | 18.955 : 18.253 | 18.697 : 9.150 | mixed-8d | 19.186 : 18.253 | 19.444 : 18.252 | 18.841 : 18.253 | 18.452 : 9.140 | mixed-16d | 18.480 : 18.253 | 19.010 : 18.252 | 19.167 : 18.252 | 16.000 : 9.134 | mixed-32d | 18.635 : 18.253 | 18.565 : 18.252 | 18.550 : 18.252 | 15.930 : 9.132 | mixed-4h | 19.079 : 18.253 | 18.990 : 18.252 | 19.157 : 18.253 | 27.834 : 9.150 | mixed-8h | 18.613 : 18.253 | 19.234 : 18.252 | 18.616 : 18.253 | 20.177 : 9.140 | mixed-16h | 18.590 : 18.253 | 19.221 : 18.252 | 19.654 : 18.253 | 17.273 : 9.135 | mixed-32h | 18.768 : 18.253 | 19.122 : 18.252 | 18.535 : 18.252 | 15.791 : 9.132 | ext3 | v3 | v4.0 | v4.1 | v4.2 | ----------|-----------------|-----------------|-----------------|-----------------| data | 34.292 : 18.253 | 33.810 : 18.252 | 33.450 : 18.253 | 33.390 : 18.254 | hole | 18.256 : 18.253 | 18.255 : 18.252 | 18.256 : 18.253 | 0.718 : 0.728 | mixed-4d | 46.818 : 18.253 | 47.140 : 18.252 | 48.385 : 18.253 | 42.887 : 9.150 | mixed-8d | 58.554 : 18.253 | 59.277 : 18.252 | 59.673 : 18.253 | 56.760 : 9.140 | mixed-16d | 44.631 : 18.253 | 44.291 : 18.252 | 44.729 : 18.253 | 40.237 : 9.135 | mixed-32d | 39.110 : 18.253 | 38.735 : 18.252 | 38.902 : 18.252 | 35.270 : 9.132 | mixed-4h | 56.396 : 18.253 | 56.387 : 18.252 | 56.573 : 18.253 | 67.661 : 9.150 | mixed-8h | 58.483 : 18.253 | 58.484 : 18.252 | 59.099 : 18.253 | 77.958 : 9.140 | mixed-16h | 42.511 : 18.253 | 42.338 : 18.252 | 42.356 : 18.252 | 51.805 : 9.135 | mixed-32h | 38.419 : 18.253 | 38.504 : 18.252 | 38.643 : 18.252 | 40.411 : 9.132 | Any questions? Anna Anna Schumaker (4): NFSD: Return eof and maxcount to nfsd4_encode_read() NFSD: Add READ_PLUS data support NFSD: Add READ_PLUS hole segment encoding NFSD: Encode a full READ_PLUS reply fs/nfsd/nfs4proc.c | 17 ++++ fs/nfsd/nfs4xdr.c | 202 +++++++++++++++++++++++++++++++++++++-------- 2 files changed, 183 insertions(+), 36 deletions(-) -- 2.24.1
