On Mon, Aug 17, 2020 at 12:53:05PM -0400, schumaker.anna@xxxxxxxxx wrote: > 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. > > - Changes since v3: > - Combine first two patches related to xdr_reserve_space_vec() > - Remove unnecessary call to svc_encode_read_payload() > > Here are the results of some performance tests I ran on some lab > machines. What's the hardware setup (do you know network and disk bandwidth?). > 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. The only numbers that look really strange are in the btrfs uncached case, in the data-only case and the mixed case that start with a hole. Do we have any idea what's up there? --b. > Read Plus Results (btrfs): > data > :... v4.1 ... Uncached ... 21.317 s, 101 MB/s, 0.63 s kern, 2% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.67 s kern, 3% cpu > :... v4.2 ... Uncached ... 28.665 s, 75 MB/s, 0.65 s kern, 2% cpu > :....... Cached ..... 18.253 s, 118 MB/s, 0.66 s kern, 3% cpu > hole > :... v4.1 ... Uncached ... 18.256 s, 118 MB/s, 0.70 s kern, 3% cpu > : :....... Cached ..... 18.254 s, 118 MB/s, 0.73 s kern, 4% cpu > :... v4.2 ... Uncached ... 0.851 s, 2.5 GB/s, 0.72 s kern, 84% cpu > :....... Cached ..... 0.847 s, 2.5 GB/s, 0.73 s kern, 86% cpu > mixed-4d > :... v4.1 ... Uncached ... 56.857 s, 38 MB/s, 0.76 s kern, 1% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.72 s kern, 3% cpu > :... v4.2 ... Uncached ... 54.455 s, 39 MB/s, 0.73 s kern, 1% cpu > :....... Cached ..... 9.215 s, 233 MB/s, 0.68 s kern, 7% cpu > mixed-8d > :... v4.1 ... Uncached ... 36.641 s, 59 MB/s, 0.68 s kern, 1% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.70 s kern, 3% cpu > :... v4.2 ... Uncached ... 33.205 s, 65 MB/s, 0.67 s kern, 2% cpu > :....... Cached ..... 9.172 s, 234 MB/s, 0.65 s kern, 7% cpu > mixed-16d > :... v4.1 ... Uncached ... 28.653 s, 75 MB/s, 0.72 s kern, 2% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.70 s kern, 3% cpu > :... v4.2 ... Uncached ... 25.748 s, 83 MB/s, 0.71 s kern, 2% cpu > :....... Cached ..... 9.150 s, 235 MB/s, 0.64 s kern, 7% cpu > mixed-32d > :... v4.1 ... Uncached ... 28.886 s, 74 MB/s, 0.67 s kern, 2% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.71 s kern, 3% cpu > :... v4.2 ... Uncached ... 24.724 s, 87 MB/s, 0.74 s kern, 2% cpu > :....... Cached ..... 9.140 s, 235 MB/s, 0.63 s kern, 6% cpu > mixed-4h > :... v4.1 ... Uncached ... 52.181 s, 41 MB/s, 0.73 s kern, 1% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.66 s kern, 3% cpu > :... v4.2 ... Uncached ... 150.341 s, 14 MB/s, 0.72 s kern, 0% cpu > :....... Cached ..... 9.216 s, 233 MB/s, 0.63 s kern, 6% cpu > mixed-8h > :... v4.1 ... Uncached ... 36.945 s, 58 MB/s, 0.68 s kern, 1% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.65 s kern, 3% cpu > :... v4.2 ... Uncached ... 79.781 s, 27 MB/s, 0.68 s kern, 0% cpu > :....... Cached ..... 9.172 s, 234 MB/s, 0.66 s kern, 7% cpu > mixed-16h > :... v4.1 ... Uncached ... 28.651 s, 75 MB/s, 0.73 s kern, 2% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.66 s kern, 3% cpu > :... v4.2 ... Uncached ... 47.428 s, 45 MB/s, 0.71 s kern, 1% cpu > :....... Cached ..... 9.150 s, 235 MB/s, 0.67 s kern, 7% cpu > mixed-32h > :... v4.1 ... Uncached ... 28.618 s, 75 MB/s, 0.69 s kern, 2% cpu > : :....... Cached ..... 18.252 s, 118 MB/s, 0.70 s kern, 3% cpu > :... v4.2 ... Uncached ... 38.813 s, 55 MB/s, 0.67 s kern, 1% cpu > :....... Cached ..... 9.140 s, 235 MB/s, 0.61 s kern, 6% cpu
