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 my own virtual machines, which does still have the slow SEEK_HOLE/SEEK_DATA behavior. A recent minimum-compiler-version patch makes installing newer kernels difficult on the lab machines I have access to, but I'll still try to collect that data since it seemed promising during my last posting (https://www.spinics.net/lists/linux-nfs/msg76487.html). I tested by reading various 2G files from a few different underlying 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 has 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. | v3 | v4.0 | v4.1 | v4.2 | ext4 | uncached: cached | uncached: cached | uncached: cached | uncached: cached | ----------|-------------------|-------------------|-------------------|-------------------| data | 2.697 : 1.365 | 2.539 : 1.482 | 2.246 : 1.595 | 2.516 : 1.716 | hole | 2.389 : 1.480 | 1.692 : 1.444 | 1.904 : 1.539 | 1.042 : 1.005 | mixed-4d | 2.426 : 1.448 | 2.468 : 1.480 | 2.258 : 1.731 | 2.408 : 1.674 | mixed-8d | 2.446 : 1.592 | 2.497 : 1.523 | 2.240 : 1.736 | 2.179 : 1.547 | mixed-16d | 2.608 : 1.575 | 2.446 : 1.582 | 2.330 : 1.670 | 2.192 : 1.488 | mixed-32d | 2.544 : 1.587 | 2.164 : 1.499 | 2.076 : 1.452 | 1.982 : 1.346 | mixed-4h | 2.591 : 1.486 | 2.233 : 1.503 | 2.190 : 1.520 | 3.679 : 1.815 | mixed-8h | 2.498 : 1.547 | 2.168 : 1.510 | 2.098 : 1.511 | 2.815 : 1.484 | mixed-16h | 2.480 : 1.664 | 2.152 : 1.597 | 2.096 : 1.537 | 2.288 : 1.580 | mixed-32h | 2.520 : 1.467 | 2.171 : 1.496 | 2.246 : 1.593 | 2.066 : 1.389 | | v3 | v4.0 | v4.1 | v4.2 | xfs | uncached: cached | uncached: cached | uncached: cached | uncached: cached | ----------|-------------------|-------------------|-------------------|-------------------| data | 2.074 : 1.353 | 2.129 : 1.489 | 2.198 : 1.564 | 2.579 : 1.719 | hole | 1.714 : 1.430 | 1.647 : 1.440 | 1.748 : 1.464 | 1.019 : 1.028 | mixed-4d | 2.699 : 1.561 | 2.782 : 1.657 | 2.800 : 1.619 | 2.848 : 2.166 | mixed-8d | 2.204 : 1.540 | 2.346 : 1.595 | 2.356 : 1.589 | 2.335 : 1.809 | mixed-16d | 2.034 : 1.445 | 2.212 : 1.561 | 2.172 : 1.546 | 2.127 : 1.658 | mixed-32d | 1.982 : 1.480 | 2.135 : 1.544 | 2.136 : 1.565 | 2.024 : 1.555 | mixed-4h | 2.600 : 1.549 | 2.790 : 1.660 | 2.745 : 1.634 | 8.949 : 2.529 | mixed-8h | 2.283 : 1.555 | 2.414 : 1.605 | 2.373 : 1.607 | 5.626 : 2.015 | mixed-16h | 2.115 : 1.512 | 2.247 : 1.593 | 2.217 : 1.608 | 3.740 : 1.803 | mixed-32h | 2.069 : 1.499 | 2.212 : 1.582 | 2.235 : 1.631 | 2.819 : 1.542 | | v3 | v4.0 | v4.1 | v4.2 | btrfs | uncached: cached | uncached: cached | uncached: cached | uncached: cached | ----------|-------------------|-------------------|-------------------|-------------------| data | 2.417 : 1.317 | 2.095 : 1.445 | 2.145 : 1.523 | 2.615 : 1.713 | hole | 2.107 : 1.483 | 2.121 : 1.496 | 2.106 : 1.461 | 1.011 : 1.061 | mixed-4d | 2.348 : 1.471 | 2.370 : 1.523 | 2.379 : 1.499 | 3.028 : 225.812 | mixed-8d | 2.227 : 1.476 | 2.231 : 1.467 | 2.272 : 1.529 | 2.723 : 36.179 | mixed-16d | 2.175 : 1.460 | 2.208 : 1.457 | 2.200 : 1.464 | 2.526 : 10.371 | mixed-32d | 2.148 : 1.501 | 2.191 : 1.468 | 2.167 : 1.471 | 2.455 : 3.367 | mixed-4h | 2.362 : 1.561 | 2.387 : 1.513 | 2.352 : 1.536 | 5.935 : 41.494 | mixed-8h | 2.241 : 1.477 | 2.251 : 1.503 | 2.256 : 1.496 | 3.672 : 10.261 | mixed-16h | 2.238 : 1.477 | 2.188 : 1.496 | 2.183 : 1.503 | 2.955 : 3.809 | mixed-32h | 2.146 : 1.490 | 2.135 : 1.523 | 2.157 : 1.557 | 2.327 : 2.088 | Anna Schumaker (6): SUNRPC: Implement xdr_reserve_space_vec() NFSD: nfsd4_encode_readv() can use xdr_reserve_space_vec() NFSD: Add READ_PLUS data support NFSD: Add READ_PLUS hole segment encoding NFSD: Return both a hole and a data segment NFSD: Encode a full READ_PLUS reply fs/nfsd/nfs4proc.c | 17 ++++ fs/nfsd/nfs4xdr.c | 169 +++++++++++++++++++++++++++++++------ include/linux/sunrpc/xdr.h | 2 + net/sunrpc/xdr.c | 45 ++++++++++ 4 files changed, 206 insertions(+), 27 deletions(-) -- 2.27.0
