On Wed, Nov 13, 2019 at 10:45:45AM +0100, Jan Kara wrote: > Thanks for the heads up! I didn't do any performance testing with the jbd2 > changes specifically and our internal performance testing grid only checks > Linus' kernel so it didn't yet even try to run that code. I'll queue some > sqlite insert tests internally with my changes to see whether I'm able to > reproduce. I don't have NVME disks available quickly but I guess SATA SSD > could do the job as well... Sorry, false alarm. What Phoronix was testing was 5.3 versus 5.4-rcX, using Ubuntu's bleeding-edge kernels. It wouldn't have any of the ext4 patches we have queued for the *next* merge window. That being said, I wasn't able to reproduce performance delta using upstream kernels, running on a Google Compute Engine VM, machtype n1-highcpu-8, using a GCE Local SSD (SCSI-attached) for the first benchmark, which I believe was the pts/sqlite benchmark using a thread count of 1: Phoronix Test Suite 9.0.1 SQLite 3.30.1 Threads / Copies: 1 Seconds < Lower Is Better 5.3.0 ..................... 225 |=========================================== 5.4.0-rc3 ................. 224 |========================================== 5.4-rc3-80-gafb2442fa429 .. 227 |=========================================== 5.4.0-rc7 ................. 223 |========================================== Processor: Intel Xeon (4 Cores / 8 Threads), Chipset: Intel 440FX 82441FX PMC, Memory: 1 x 7373 MB RAM, Disk: 11GB PersistentDisk + 403GB EphemeralDisk, Network: Red Hat Virtio device OS: Debian 10, Kernel: 5.4.0-rc3-xfstests (x86_64) 20191113, Compiler: GCC 8.3.0, File-System: ext4, System Layer: KVM This was done using an extension to a gce-xfstests test appliance, to which I hope to be adding an automation engine where it will kexec into a series of kernels, run the benchmarks and then spit out the report somewhere. For now, the benchmarks are run manually. (Adding commentary and click-baity titles is left as an exercise to the reader. :-) - Ted P.S. For all that I like to make snarky comments about Phoronix.com, I have to admit Michael Larabel has done a pretty good job with his performance test engine. I probably would have choosen a different implementation than PHP, and I'd have added an explicit way to specify the file system to be tested other than mounting it on top of /var/lib/phoronix-test-suite, and at least have the option of placing the benchmarks' build trees and binaries in a different location than the file system under test. But that being said, he's collecting a decent set of benchmark tools, and it is pretty cool that it has an automated way of collecting the benchmark results, including the pretty graphs suitable for web articles and conference slide decks ("and now, we turn to the rigged benchmarks section of the presentation designed to show my new feature in the best possible light...").