On Wed, Jun 10, 2020 at 4:24 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Wed, Jun 10, 2020 at 3:59 PM Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Mon, Jun 08, 2020 at 11:39:26PM +0300, Amir Goldstein wrote: > > > > Let me add your optimizations on top of my branch with the needed > > > > adaptations and send you a branch for testing. > > > > > > https://github.com/amir73il/linux/commits/fsnotify_name-for-mel > > > > > > > Sorry for the delay getting back. The machine was busy with other tests > > and it took a while to reach this on the queue. Fairly good news > > > > hackbench-process-pipes > > 5.7.0 5.7.0 5.7.0 5.7.0 > > vanilla fastfsnotify-v1r1 amir-20200608 amir-for-mel > > Amean 1 0.4837 ( 0.00%) 0.4630 * 4.27%* 0.4967 * -2.69%* 0.4680 ( 3.24%) > > Amean 3 1.5447 ( 0.00%) 1.4557 ( 5.76%) 1.6587 * -7.38%* 1.4807 ( 4.14%) > > Amean 5 2.6037 ( 0.00%) 2.4363 ( 6.43%) 2.6400 ( -1.40%) 2.4900 ( 4.37%) > > Amean 7 3.5987 ( 0.00%) 3.4757 ( 3.42%) 3.9040 * -8.48%* 3.5130 ( 2.38%) > > Amean 12 5.8267 ( 0.00%) 5.6983 ( 2.20%) 6.2593 ( -7.43%) 5.6967 ( 2.23%) > > Amean 18 8.4400 ( 0.00%) 8.1327 ( 3.64%) 8.9940 ( -6.56%) 7.7240 * 8.48%* > > Amean 24 11.0187 ( 0.00%) 10.0290 * 8.98%* 11.7247 * -6.41%* 9.5793 * 13.06%* > > Amean 30 13.1013 ( 0.00%) 12.8510 ( 1.91%) 14.0290 * -7.08%* 12.1630 ( 7.16%) > > Amean 32 13.9190 ( 0.00%) 13.2410 ( 4.87%) 14.7140 * -5.71%* 13.2457 * 4.84%* > > > > First two sets of results are vanilla kernel and just my patch respectively > > to have two baselines. amir-20200608 is the first git branch you pointed > > me to and amir-for-mel is this latest branch. Comparing the optimisation > > and your series, we get > > > > hackbench-process-pipes > > 5.7.0 5.7.0 > > fastfsnotify-v1r1 amir-for-mel > > Amean 1 0.4630 ( 0.00%) 0.4680 ( -1.08%) > > Amean 3 1.4557 ( 0.00%) 1.4807 ( -1.72%) > > Amean 5 2.4363 ( 0.00%) 2.4900 ( -2.20%) > > Amean 7 3.4757 ( 0.00%) 3.5130 ( -1.07%) > > Amean 12 5.6983 ( 0.00%) 5.6967 ( 0.03%) > > Amean 18 8.1327 ( 0.00%) 7.7240 ( 5.03%) > > Amean 24 10.0290 ( 0.00%) 9.5793 ( 4.48%) > > Amean 30 12.8510 ( 0.00%) 12.1630 ( 5.35%) > > Amean 32 13.2410 ( 0.00%) 13.2457 ( -0.04%) > > > > As you can see, your patches with the optimisation layered on top is > > comparable to just the optimisation on its own. It's not universally > > better but it would not look like a regression when comparing releases. > > The differences are mostly within the noise as there is some variability > > involved for this workload so I would not worry too much about it (caveats > > are other machines may be different as well as other workloads). > > Excellent! > Thanks for verifying. > > TBH, this result is not surprising, because despite all the changes from > fastfsnotify-v1r1 to amir-for-mel, the code that is executed when there > are no watches should be quite similar. Without any unexpected compiler > optimizations that may differ between our versions, fsnotify hooks called > for directories should execute the exact same code. > > fsnotify hooks called for non-directories (your workload) should execute > almost the same code. I spotted one additional test for access to > d_inode and one additional test of: > dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED > in the entry to __fsnotify_parent(). > > > A minor > > issue is that this is probably a bisection hazard. If a series is merged > > and LKP points the finger somewhere in the middle of your series then > > I suggest you ask them to test the optimisation commit ID to see if the > > regression goes away. > > > > No worries. I wasn't planning on submitted the altered patch. > I just wanted to let you test the final result. > I will apply your change before my series and make sure to keep > optimizations while my changes are applied on top of that. > FYI, just posted your patch with a minor style change at the bottom of my prep patch series. Thanks, Amir.
