Issue #2288 has been updated by Jan Lentfer. Status changed from New to Feedback Priority changed from High to Low
I tried to reproduce it and although I am still sure my initial testing was done correct I can't. I will put this on a hold for now, because of lack of time. I will try to return to it later ---------------------------------------- Bug #2288: Random IO performance loss introduced since January 1st http://bugs.dragonflybsd.org/issues/2288 Author: Jan Lentfer Status: Feedback Priority: Low Assignee: Category: Target version: Running pgbench I found that performance had dropped by 13%. To figure out the reason I did some sysbench io tests (see below). All tests were run using the same test files, same hardware etc etc 3 times in a row. As the results were consistent I am only pasting the result of the last run of each set. The cause for the performance loss must have been introduced some time between Jan 1st and Jan 23rd. 2.12: atom# sysbench --test=fileio --file-num=8 --file-total-size=6G --file-test-mode=rndrd --max-requests=0 --max-time=300 run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Extra file open flags: 0 8 files, 768Mb each 6Gb total file size Block size 16Kb Number of random requests for random IO: 0 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 100 requests. Calling fsync() at the end of test, Enabled. Using synchronous I/O mode Doing random read test Threads started! Time limit exceeded, exiting... Done. Operations performed: 50389 Read, 0 Write, 0 Other = 50389 Total Read 787.33Mb Written 0b Total transferred 787.33Mb (2.6244Mb/sec) 167.96 Requests/sec executed Test execution summary: total time: 300.0027s total number of events: 50389 total time taken by event execution: 299.7273 per-request statistics: min: 0.02ms avg: 5.95ms max: 77.80ms approx. 95 percentile: 12.05ms Threads fairness: events (avg/stddev): 50389.0000/0.00 execution time (avg/stddev): 299.7273/0.00 2.13 g47f97 (new year's eve): atom# sysbench --test=fileio --file-num=8 --file-total-size=6G --file-test-mode=rndrd --max-requests=0 --max-time=300 run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Extra file open flags: 0 8 files, 768Mb each 6Gb total file size Block size 16Kb Number of random requests for random IO: 0 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 100 requests. Calling fsync() at the end of test, Enabled. Using synchronous I/O mode Doing random read test Threads started! Time limit exceeded, exiting... Done. Operations performed: 50037 Read, 0 Write, 0 Other = 50037 Total Read 781.83Mb Written 0b Total transferred 781.83Mb (2.6061Mb/sec) 166.79 Requests/sec executed Test execution summary: total time: 300.0040s total number of events: 50037 total time taken by event execution: 299.7070 per-request statistics: min: 0.02ms avg: 5.99ms max: 104.73ms approx. 95 percentile: 12.06ms Threads fairness: events (avg/stddev): 50037.0000/0.00 execution time (avg/stddev): 299.7070/0.00 2.13 (from Jan 23rd incl. the sili/ahci fix): atom# sysbench --test=fileio --file-num=8 --file-total-size=6G --file-test-mode=rndrd --max-requests=0 --max-time=300 run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Extra file open flags: 0 8 files, 768Mb each 6Gb total file size Block size 16Kb Number of random requests for random IO: 0 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 100 requests. Calling fsync() at the end of test, Enabled. Using synchronous I/O mode Doing random read test Threads started! Time limit exceeded, exiting... Done. Operations performed: 39898 Read, 0 Write, 0 Other = 39898 Total Read 623.41Mb Written 0b Total transferred 623.41Mb (2.078Mb/sec) 132.99 Requests/sec executed Test execution summary: total time: 300.0038s total number of events: 39898 total time taken by event execution: 299.7377 per-request statistics: min: 0.02ms avg: 7.51ms max: 61.00ms approx. 95 percentile: 12.27ms Threads fairness: events (avg/stddev): 39898.0000/0.00 execution time (avg/stddev): 299.7377/0.00 -- You have received this notification because you have either subscribed to it, or are involved in it. To change your notification preferences, please click here: http://bugs.dragonflybsd.org/my/account
