From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> These patches add client support for the READ_PLUS operation, which breaks read requests into several "data" and "hole" segments when replying to the client. I also add a "noreadplus" mount option to allow users to disable the new operation if it becomes a problem, similar to the "nordirplus" mount option that we already have. 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 (7): SUNRPC: Split out a function for setting current page SUNRPC: Add the ability to expand holes in data pages SUNRPC: Add the ability to shift data to a specific offset NFS: Add READ_PLUS data segment support NFS: Add READ_PLUS hole segment decoding NFS: Decode multiple READ_PLUS segments NFS: Add a mount option for READ_PLUS fs/nfs/fs_context.c | 14 +++ fs/nfs/nfs42xdr.c | 169 +++++++++++++++++++++++++ fs/nfs/nfs4client.c | 3 + fs/nfs/nfs4proc.c | 32 ++++- fs/nfs/nfs4xdr.c | 1 + include/linux/nfs4.h | 2 +- include/linux/nfs_fs_sb.h | 2 + include/linux/nfs_xdr.h | 2 +- include/linux/sunrpc/xdr.h | 2 + net/sunrpc/xdr.c | 244 ++++++++++++++++++++++++++++++++++++- 10 files changed, 464 insertions(+), 7 deletions(-) -- 2.24.1
