Raw results: every run, as printed by bench.sh. Nothing was dropped. Builds: master 4545cee303c ("base"), and the same commit with the v36 series ("v36"). "v36full" = v36 with the heap read stream opened with READ_STREAM_FULL instead of READ_STREAM_DEFAULT (one line; measured only in the first set). -O2, no assertions. The first four sets were run before the builds were redone with --with-liburing; io_method=worker does not use it, and the worker control in the last sets matches the earlier worker numbers. Machine: AMD Ryzen AI 9 HX 370 (24 threads), 30 GB RAM, Linux 7.1.12, Kingston SKC3000D NVMe. Data directory on btrfs with zstd compression for the "local NVMe" sets; on ext4 over dm-delay over a loop device (direct I/O, nocow backing file) for the "delay" sets. 8 kB O_DIRECT reads on that device took 0.16 / 1.25 / 2.27 ms at a delay of 0 / 1 / 2 ms. Table: 8M rows, 163,266 heap pages. pg_stats correlation: id 1.0000, b 1.0000, a -0.0095. Each index is 21,937 pages. Server: shared_buffers 512MB, track_io_timing on, jit off, autovacuum off, max_parallel_workers_per_gather 0; defaults otherwise (io_method worker, io_min_workers 2, io_max_workers 8, effective_io_concurrency 16) unless a section says so. Server stopped, data files evicted from the page cache and server started in a 900 MB memory cgroup before every run; build order rotated each round. Columns: scenario, build, execution time | EXPLAIN Buffers | EXPLAIN (IO) Prefetch line | EXPLAIN (IO) I/O line | read requests that reached the device during the query (only where "dev:" is shown; from /sys/block/dm-0/stat). Scenarios: cold_uncorr = t.a BETWEEN 1000000 AND 1019999 (uncorrelated); cold_near = t.b BETWEEN 1000000 AND 1399999 (+/-50 row jitter); cold_corr = t.id BETWEEN 1000000 AND 1399999 (same rows' heap range, no jitter); warm25_uncorr = cold_uncorr after pg_prewarm of the index and of 8 of every 40 heap blocks. Block sequence for the 400k-row range (blockseq.sql): index distinct blocks handed to the stream breaks in contiguity id 8,164 8,164 0 b 8,166 136,837 127,380 ======== local NVMe, uncorrelated and nearly correlated, 3 builds ======== file: results.txt cold_uncorr base 1652.229 ms | shared read=20057 | | cold_uncorr v36 841.913 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=2575 size=1.00 in-progress=15.99 cold_uncorr v36full 772.660 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=3031 size=1.00 in-progress=15.99 cold_uncorr v36 757.465 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=2642 size=1.00 in-progress=15.99 cold_uncorr v36full 809.596 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=3037 size=1.00 in-progress=15.99 cold_uncorr base 1394.250 ms | shared read=20057 | | cold_uncorr v36full 707.809 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=2964 size=1.00 in-progress=15.99 cold_uncorr base 1600.562 ms | shared read=20057 | | cold_uncorr v36 538.298 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=4346 size=1.00 in-progress=15.99 cold_near base 287.991 ms | shared hit=128671 read=9262 | | cold_near v36 326.905 ms | shared hit=128664 read=9262 | Prefetch: avg=207.18 max=271 capacity=272 | I/O: count=11858 waits=76 size=1.00 in-progress=15.96 cold_near v36full 256.034 ms | shared hit=128657 read=9262 | Prefetch: avg=165.87 max=271 capacity=272 | I/O: count=15289 waits=65 size=1.00 in-progress=15.97 cold_near v36 288.212 ms | shared hit=128663 read=9262 | Prefetch: avg=181.41 max=271 capacity=272 | I/O: count=13638 waits=53 size=1.00 in-progress=15.98 cold_near v36full 214.332 ms | shared hit=128671 read=9262 | Prefetch: avg=153.73 max=240 capacity=272 | I/O: count=14896 waits=26 size=1.00 in-progress=15.96 cold_near base 290.064 ms | shared hit=128671 read=9262 | | cold_near v36full 278.529 ms | shared hit=128666 read=9262 | Prefetch: avg=184.40 max=271 capacity=272 | I/O: count=12868 waits=45 size=1.00 in-progress=15.95 cold_near base 243.609 ms | shared hit=128671 read=9262 | | cold_near v36 196.073 ms | shared hit=128668 read=9262 | Prefetch: avg=156.58 max=271 capacity=272 | I/O: count=14592 waits=33 size=1.00 in-progress=15.97 warm25_uncorr base 1457.063 ms | shared hit=4052 read=16005 | | warm25_uncorr v36 500.662 ms | shared hit=4052 read=16005 | Prefetch: avg=20.34 max=27 capacity=272 | I/O: count=15995 waits=2294 size=1.00 in-progress=15.99 warm25_uncorr v36full 670.477 ms | shared hit=4052 read=16005 | Prefetch: avg=20.34 max=27 capacity=272 | I/O: count=15995 waits=2222 size=1.00 in-progress=15.99 warm25_uncorr v36 703.510 ms | shared hit=4052 read=16005 | Prefetch: avg=20.33 max=27 capacity=272 | I/O: count=15995 waits=1884 size=1.00 in-progress=15.99 warm25_uncorr v36full 406.187 ms | shared hit=4052 read=16005 | Prefetch: avg=20.34 max=27 capacity=272 | I/O: count=15995 waits=2675 size=1.00 in-progress=15.99 warm25_uncorr base 1492.717 ms | shared hit=4052 read=16005 | | warm25_uncorr v36full 482.859 ms | shared hit=4052 read=16005 | Prefetch: avg=20.34 max=27 capacity=272 | I/O: count=15995 waits=1966 size=1.00 in-progress=15.99 warm25_uncorr base 1513.032 ms | shared hit=4052 read=16005 | | warm25_uncorr v36 500.280 ms | shared hit=4052 read=16005 | Prefetch: avg=20.34 max=27 capacity=272 | I/O: count=15995 waits=2280 size=1.00 in-progress=15.99 ======== local NVMe, correlated index ======== file: results_corr.txt cold_corr base 195.436 ms | shared read=9260 | | cold_corr v36 227.077 ms | shared read=9260 | Prefetch: avg=208.18 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=13.38 cold_corr v36 230.955 ms | shared read=9260 | Prefetch: avg=155.80 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=10.13 cold_corr base 189.830 ms | shared read=9260 | | cold_corr base 222.918 ms | shared read=9260 | | cold_corr v36 212.621 ms | shared read=9260 | Prefetch: avg=117.64 max=128 capacity=272 | I/O: count=514 waits=7 size=15.88 in-progress=7.77 cold_corr v36 149.056 ms | shared read=9260 | Prefetch: avg=202.57 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=13.04 cold_corr base 179.225 ms | shared read=9260 | | cold_near base 275.315 ms | shared hit=128671 read=9262 | | cold_near v36 234.802 ms | shared hit=128662 read=9262 | Prefetch: avg=171.57 max=271 capacity=272 | I/O: count=14082 waits=49 size=1.00 in-progress=15.98 cold_near v36 201.737 ms | shared hit=128670 read=9262 | Prefetch: avg=167.34 max=257 capacity=272 | I/O: count=13772 waits=29 size=1.00 in-progress=15.98 cold_near base 227.889 ms | shared hit=128671 read=9262 | | cold_near base 236.495 ms | shared hit=128671 read=9262 | | cold_near v36 341.524 ms | shared hit=128653 read=9262 | Prefetch: avg=215.64 max=271 capacity=272 | I/O: count=11808 waits=89 size=1.00 in-progress=15.97 cold_near v36 316.128 ms | shared hit=128662 read=9262 | Prefetch: avg=210.53 max=271 capacity=272 | I/O: count=11376 waits=57 size=1.00 in-progress=15.95 cold_near base 243.181 ms | shared hit=128671 read=9262 | | ======== local NVMe, cgroup IOReadIOPSMax=3000 ======== file: results_iops3000.txt NOT VALID: the cap was not enforced on this btrfs volume (20k random reads ran at ~11k IOPS). Kept only for completeness. cold_corr base 172.250 ms | shared read=9260 | | cold_corr v36 125.666 ms | shared read=9260 | Prefetch: avg=235.44 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=15.07 cold_corr v36 189.824 ms | shared read=9260 | Prefetch: avg=219.84 max=271 capacity=272 | I/O: count=514 waits=9 size=15.88 in-progress=13.86 cold_corr base 223.343 ms | shared read=9260 | | cold_corr base 232.947 ms | shared read=9260 | | cold_corr v36 231.199 ms | shared read=9260 | Prefetch: avg=117.51 max=128 capacity=272 | I/O: count=514 waits=7 size=15.88 in-progress=7.76 cold_corr v36 158.269 ms | shared read=9260 | Prefetch: avg=227.44 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=14.58 cold_corr base 304.670 ms | shared read=9260 | | cold_near base 287.228 ms | shared hit=128671 read=9262 | | cold_near v36 317.635 ms | shared hit=128657 read=9262 | Prefetch: avg=215.91 max=271 capacity=272 | I/O: count=10927 waits=61 size=1.00 in-progress=15.97 cold_near v36 355.832 ms | shared hit=128657 read=9262 | Prefetch: avg=202.60 max=271 capacity=272 | I/O: count=12780 waits=86 size=1.00 in-progress=15.96 cold_near base 319.196 ms | shared hit=128671 read=9262 | | cold_near base 255.153 ms | shared hit=128671 read=9262 | | cold_near v36 249.823 ms | shared hit=128659 read=9262 | Prefetch: avg=202.12 max=271 capacity=272 | I/O: count=12149 waits=83 size=1.00 in-progress=15.96 cold_near v36 387.327 ms | shared hit=128642 read=9262 | Prefetch: avg=203.17 max=271 capacity=272 | I/O: count=13222 waits=151 size=1.00 in-progress=15.97 cold_near base 209.653 ms | shared hit=128671 read=9262 | | ======== delay device, read delay 0 ms ======== file: results_delay0ms.txt cold_uncorr base 3805.275 ms | shared read=20057 | | cold_uncorr v36 1028.881 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5824 size=1.00 in-progress=15.99 cold_uncorr v36 899.596 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=7369 size=1.00 in-progress=15.99 cold_uncorr base 3127.393 ms | shared read=20057 | | cold_uncorr base 3036.812 ms | shared read=20057 | | cold_uncorr v36 993.370 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=7364 size=1.00 in-progress=15.99 cold_near base 291.340 ms | shared hit=128671 read=9262 | | cold_near v36 251.756 ms | shared hit=128658 read=9262 | Prefetch: avg=126.84 max=223 capacity=272 | I/O: count=18240 waits=92 size=1.00 in-progress=15.97 cold_near v36 193.829 ms | shared hit=128657 read=9262 | Prefetch: avg=123.14 max=251 capacity=272 | I/O: count=19646 waits=105 size=1.00 in-progress=15.98 cold_near base 314.334 ms | shared hit=128671 read=9262 | | cold_near base 311.838 ms | shared hit=128671 read=9262 | | cold_near v36 339.489 ms | shared hit=128647 read=9262 | Prefetch: avg=125.22 max=257 capacity=272 | I/O: count=18726 waits=127 size=1.00 in-progress=15.96 cold_corr base 707.670 ms | shared read=9260 | | cold_corr v36 163.749 ms | shared read=9260 | Prefetch: avg=255.23 max=271 capacity=272 | I/O: count=514 waits=26 size=15.88 in-progress=15.42 cold_corr v36 216.618 ms | shared read=9260 | Prefetch: avg=209.31 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=13.45 cold_corr base 208.080 ms | shared read=9260 | | cold_corr base 284.302 ms | shared read=9260 | | cold_corr v36 187.470 ms | shared read=9260 | Prefetch: avg=255.92 max=271 capacity=272 | I/O: count=514 waits=13 size=15.88 in-progress=15.47 ======== delay device, read delay 1 ms ======== file: results_delay1ms.txt cold_uncorr base 24141.171 ms | shared read=20057 | | cold_uncorr v36 3182.943 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5407 size=1.00 in-progress=15.99 cold_uncorr v36 3712.458 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5254 size=1.00 in-progress=15.99 cold_uncorr base 23405.470 ms | shared read=20057 | | cold_uncorr base 24746.832 ms | shared read=20057 | | cold_uncorr v36 3278.661 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5444 size=1.00 in-progress=15.99 cold_near base 339.626 ms | shared hit=128671 read=9262 | | cold_near v36 405.476 ms | shared hit=128615 read=9262 | Prefetch: avg=109.79 max=239 capacity=272 | I/O: count=21377 waits=311 size=1.00 in-progress=15.96 cold_near v36 367.895 ms | shared hit=128600 read=9262 | Prefetch: avg=106.19 max=253 capacity=272 | I/O: count=22246 waits=313 size=1.00 in-progress=15.98 cold_near base 346.190 ms | shared hit=128671 read=9262 | | cold_near base 432.407 ms | shared hit=128671 read=9262 | | cold_near v36 470.594 ms | shared hit=128594 read=9262 | Prefetch: avg=107.58 max=271 capacity=272 | I/O: count=22990 waits=413 size=1.00 in-progress=15.97 cold_corr base 361.479 ms | shared read=9260 | | cold_corr v36 208.178 ms | shared read=9260 | Prefetch: avg=252.81 max=271 capacity=272 | I/O: count=514 waits=33 size=15.88 in-progress=15.32 cold_corr v36 229.028 ms | shared read=9260 | Prefetch: avg=254.71 max=271 capacity=272 | I/O: count=514 waits=94 size=15.88 in-progress=15.40 cold_corr base 424.259 ms | shared read=9260 | | cold_corr base 387.988 ms | shared read=9260 | | cold_corr v36 209.070 ms | shared read=9260 | Prefetch: avg=248.68 max=271 capacity=272 | I/O: count=514 waits=63 size=15.88 in-progress=15.08 ======== delay device, read delay 2 ms ======== file: results_delay2ms.txt cold_uncorr base 43637.677 ms | shared read=20057 | | cold_uncorr v36 5556.318 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5566 size=1.00 in-progress=15.99 cold_uncorr v36 5579.381 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5483 size=1.00 in-progress=15.99 cold_uncorr base 45416.578 ms | shared read=20057 | | cold_uncorr base 44532.883 ms | shared read=20057 | | cold_uncorr v36 5590.942 ms | shared read=20057 | Prefetch: avg=15.99 max=16 capacity=272 | I/O: count=19997 waits=5528 size=1.00 in-progress=15.99 cold_near base 771.451 ms | shared hit=128671 read=9262 | | cold_near v36 978.947 ms | shared hit=128560 read=9262 | Prefetch: avg=104.92 max=271 capacity=272 | I/O: count=23412 waits=534 size=1.00 in-progress=15.98 cold_near v36 899.546 ms | shared hit=128563 read=9262 | Prefetch: avg=103.43 max=271 capacity=272 | I/O: count=23438 waits=578 size=1.00 in-progress=15.98 cold_near base 735.301 ms | shared hit=128671 read=9262 | | cold_near base 634.483 ms | shared hit=128671 read=9262 | | cold_near v36 1039.431 ms | shared hit=128553 read=9262 | Prefetch: avg=97.32 max=271 capacity=272 | I/O: count=25488 waits=614 size=1.00 in-progress=15.99 cold_corr base 695.125 ms | shared read=9260 | | cold_corr v36 308.994 ms | shared read=9260 | Prefetch: avg=256.36 max=271 capacity=272 | I/O: count=514 waits=115 size=15.88 in-progress=15.49 cold_corr v36 314.678 ms | shared read=9260 | Prefetch: avg=254.43 max=271 capacity=272 | I/O: count=514 waits=143 size=15.88 in-progress=15.39 cold_corr base 734.187 ms | shared read=9260 | | cold_corr base 674.151 ms | shared read=9260 | | cold_corr v36 340.542 ms | shared read=9260 | Prefetch: avg=254.99 max=271 capacity=272 | I/O: count=514 waits=119 size=15.88 in-progress=15.42 ======== delay 2 ms, with device request counts ======== file: results_delay2ms_dev.txt cold_near base 788.897 ms | shared hit=128671 read=9262 | | | dev: reads=697 merged=0 kB/read=109.2 cold_near v36 811.223 ms | shared hit=128574 read=9262 | Prefetch: avg=98.97 max=271 capacity=272 | I/O: count=24048 waits=504 size=1.00 in-progress=15.97 | dev: reads=787 merged=0 kB/read=96.5 cold_near v36 732.594 ms | shared hit=128582 read=9262 | Prefetch: avg=98.77 max=271 capacity=272 | I/O: count=23552 waits=477 size=1.00 in-progress=15.97 | dev: reads=756 merged=0 kB/read=100.6 cold_near base 651.234 ms | shared hit=128671 read=9262 | | | dev: reads=692 merged=0 kB/read=109.9 cold_near base 839.158 ms | shared hit=128671 read=9262 | | | dev: reads=692 merged=0 kB/read=109.9 cold_near v36 1287.441 ms | shared hit=128553 read=9262 | Prefetch: avg=100.10 max=271 capacity=272 | I/O: count=24236 waits=541 size=1.00 in-progress=15.97 | dev: reads=874 merged=0 kB/read=87.0 cold_corr base 816.989 ms | shared read=9260 | | | dev: reads=695 merged=0 kB/read=109.5 cold_corr v36 324.828 ms | shared read=9260 | Prefetch: avg=256.17 max=271 capacity=272 | I/O: count=514 waits=157 size=15.88 in-progress=15.47 | dev: reads=691 merged=0 kB/read=110.0 cold_corr v36 339.526 ms | shared read=9260 | Prefetch: avg=255.74 max=271 capacity=272 | I/O: count=514 waits=155 size=15.88 in-progress=15.46 | dev: reads=690 merged=0 kB/read=109.9 cold_corr base 615.241 ms | shared read=9260 | | | dev: reads=692 merged=0 kB/read=109.7 cold_corr base 652.548 ms | shared read=9260 | | | dev: reads=692 merged=0 kB/read=109.7 cold_corr v36 327.421 ms | shared read=9260 | Prefetch: avg=255.68 max=271 capacity=272 | I/O: count=514 waits=145 size=15.88 in-progress=15.46 | dev: reads=690 merged=0 kB/read=110.1 ======== delay 2 ms, nearly correlated, 10 rounds ======== file: results_delay2ms_near10.txt cold_near base 628.479 ms | shared hit=128671 read=9262 | | | dev: reads=688 merged=0 kB/read=110.2 cold_near v36 842.861 ms | shared hit=128573 read=9262 | Prefetch: avg=98.14 max=271 capacity=272 | I/O: count=24207 waits=492 size=1.00 in-progress=15.98 | dev: reads=809 merged=0 kB/read=94.0 cold_near v36 786.284 ms | shared hit=128578 read=9262 | Prefetch: avg=96.68 max=271 capacity=272 | I/O: count=24434 waits=484 size=1.00 in-progress=15.98 | dev: reads=795 merged=0 kB/read=95.5 cold_near base 719.211 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 670.891 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 867.353 ms | shared hit=128560 read=9262 | Prefetch: avg=92.20 max=271 capacity=272 | I/O: count=25906 waits=519 size=1.00 in-progress=15.95 | dev: reads=848 merged=0 kB/read=89.7 cold_near v36 731.318 ms | shared hit=128570 read=9262 | Prefetch: avg=96.11 max=257 capacity=272 | I/O: count=24695 waits=483 size=1.00 in-progress=15.98 | dev: reads=767 merged=0 kB/read=99.2 cold_near base 711.721 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 723.261 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 911.945 ms | shared hit=128572 read=9262 | Prefetch: avg=96.35 max=271 capacity=272 | I/O: count=24884 waits=547 size=1.00 in-progress=15.99 | dev: reads=883 merged=0 kB/read=86.1 cold_near v36 961.812 ms | shared hit=128552 read=9262 | Prefetch: avg=104.96 max=271 capacity=272 | I/O: count=23347 waits=572 size=1.00 in-progress=15.97 | dev: reads=865 merged=0 kB/read=87.9 cold_near base 720.178 ms | shared hit=128671 read=9262 | | | dev: reads=706 merged=0 kB/read=107.8 cold_near base 740.722 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 1038.626 ms | shared hit=128550 read=9262 | Prefetch: avg=104.01 max=271 capacity=272 | I/O: count=23466 waits=537 size=1.00 in-progress=15.97 | dev: reads=886 merged=0 kB/read=86.0 cold_near v36 858.799 ms | shared hit=128564 read=9262 | Prefetch: avg=99.06 max=271 capacity=272 | I/O: count=23972 waits=506 size=1.00 in-progress=15.99 | dev: reads=816 merged=0 kB/read=93.1 cold_near base 701.321 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 618.703 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 912.249 ms | shared hit=128557 read=9262 | Prefetch: avg=101.50 max=271 capacity=272 | I/O: count=23776 waits=541 size=1.00 in-progress=15.99 | dev: reads=844 merged=0 kB/read=90.1 cold_near v36 1173.631 ms | shared hit=128549 read=9262 | Prefetch: avg=117.41 max=271 capacity=272 | I/O: count=20690 waits=536 size=1.00 in-progress=15.98 | dev: reads=829 merged=0 kB/read=91.8 cold_near base 869.266 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 ======== delay 2 ms, io_min_workers=2 io_max_workers=8, eic 16 ======== file: results_2ms_w2-8_eic16.txt cold_near base 715.714 ms | shared hit=128671 read=9262 | | | dev: reads=693 merged=0 kB/read=109.8 cold_near v36 648.691 ms | shared hit=128590 read=9262 | Prefetch: avg=101.58 max=252 capacity=272 | I/O: count=23024 waits=415 size=1.00 in-progress=15.94 | dev: reads=735 merged=0 kB/read=103.5 cold_near v36 774.553 ms | shared hit=128580 read=9262 | Prefetch: avg=100.16 max=271 capacity=272 | I/O: count=23397 waits=476 size=1.00 in-progress=15.97 | dev: reads=773 merged=0 kB/read=98.3 cold_near base 687.415 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 708.205 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 787.544 ms | shared hit=128575 read=9262 | Prefetch: avg=89.96 max=204 capacity=272 | I/O: count=25970 waits=454 size=1.00 in-progress=15.99 | dev: reads=727 merged=0 kB/read=104.6 cold_near v36 879.530 ms | shared hit=128571 read=9262 | Prefetch: avg=96.44 max=271 capacity=272 | I/O: count=24745 waits=541 size=1.00 in-progress=15.94 | dev: reads=836 merged=0 kB/read=91.0 cold_near base 715.530 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 667.619 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 813.518 ms | shared hit=128563 read=9262 | Prefetch: avg=93.95 max=271 capacity=272 | I/O: count=25209 waits=504 size=1.00 in-progress=15.97 | dev: reads=820 merged=0 kB/read=92.8 ======== delay 2 ms, io_min_workers=io_max_workers=8, eic 16 ======== file: results_2ms_w8-8_eic16.txt cold_near base 680.033 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 765.969 ms | shared hit=128574 read=9262 | Prefetch: avg=96.75 max=271 capacity=272 | I/O: count=24415 waits=490 size=1.00 in-progress=15.95 | dev: reads=782 merged=0 kB/read=97.3 cold_near v36 797.225 ms | shared hit=128570 read=9262 | Prefetch: avg=98.43 max=271 capacity=272 | I/O: count=24208 waits=500 size=1.00 in-progress=15.97 | dev: reads=801 merged=0 kB/read=94.9 cold_near base 731.915 ms | shared hit=128671 read=9262 | | | dev: reads=689 merged=0 kB/read=110.3 cold_near base 682.726 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 838.295 ms | shared hit=128567 read=9262 | Prefetch: avg=95.81 max=271 capacity=272 | I/O: count=24863 waits=506 size=1.00 in-progress=15.99 | dev: reads=819 merged=0 kB/read=92.9 cold_near v36 752.924 ms | shared hit=128570 read=9262 | Prefetch: avg=97.97 max=259 capacity=272 | I/O: count=24091 waits=513 size=1.00 in-progress=15.97 | dev: reads=790 merged=0 kB/read=96.3 cold_near base 694.124 ms | shared hit=128671 read=9262 | | | dev: reads=686 merged=0 kB/read=110.8 cold_near base 755.660 ms | shared hit=128671 read=9262 | | | dev: reads=688 merged=0 kB/read=110.2 cold_near v36 845.281 ms | shared hit=128565 read=9262 | Prefetch: avg=99.84 max=271 capacity=272 | I/O: count=23835 waits=507 size=1.00 in-progress=15.94 | dev: reads=818 merged=0 kB/read=93.0 ======== delay 2 ms, io_min_workers=io_max_workers=32, eic 16 ======== file: results_2ms_w32-32_eic16.txt cold_near base 697.190 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 742.540 ms | shared hit=128597 read=9262 | Prefetch: avg=96.79 max=203 capacity=272 | I/O: count=24309 waits=417 size=1.00 in-progress=15.98 | dev: reads=736 merged=0 kB/read=103.0 cold_near v36 855.282 ms | shared hit=128570 read=9262 | Prefetch: avg=96.26 max=271 capacity=272 | I/O: count=24491 waits=509 size=1.00 in-progress=15.96 | dev: reads=810 merged=0 kB/read=93.8 cold_near base 683.933 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 658.507 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 677.703 ms | shared hit=128588 read=9262 | Prefetch: avg=96.10 max=248 capacity=272 | I/O: count=24558 waits=454 size=1.00 in-progress=15.97 | dev: reads=737 merged=0 kB/read=103.0 cold_near v36 922.887 ms | shared hit=128558 read=9262 | Prefetch: avg=106.31 max=271 capacity=272 | I/O: count=22762 waits=556 size=1.00 in-progress=15.98 | dev: reads=846 merged=0 kB/read=89.9 cold_near base 698.108 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.1 cold_near base 665.118 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 791.373 ms | shared hit=128577 read=9262 | Prefetch: avg=97.25 max=271 capacity=272 | I/O: count=24259 waits=501 size=1.00 in-progress=15.98 | dev: reads=786 merged=0 kB/read=96.8 ======== delay 2 ms, io_min_workers=io_max_workers=32, eic 64 ======== file: results_2ms_w32-32_eic64.txt cold_near base 731.686 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 831.352 ms | shared hit=128643 read=9262 | Prefetch: avg=184.70 max=375 capacity=376 | I/O: count=48512 waits=460 size=1.00 in-progress=63.79 | dev: reads=912 merged=0 kB/read=83.4 cold_near v36 913.928 ms | shared hit=128632 read=9262 | Prefetch: avg=179.99 max=375 capacity=376 | I/O: count=49618 waits=484 size=1.00 in-progress=63.66 | dev: reads=965 merged=0 kB/read=78.8 cold_near base 697.416 ms | shared hit=128671 read=9262 | | | dev: reads=704 merged=0 kB/read=108.2 cold_near base 743.645 ms | shared hit=128671 read=9262 | | | dev: reads=691 merged=0 kB/read=110.1 cold_near v36 843.014 ms | shared hit=128630 read=9262 | Prefetch: avg=184.61 max=375 capacity=376 | I/O: count=48340 waits=473 size=1.00 in-progress=63.76 | dev: reads=885 merged=0 kB/read=85.9 cold_near v36 715.381 ms | shared hit=128629 read=9262 | Prefetch: avg=197.24 max=375 capacity=376 | I/O: count=45490 waits=379 size=1.00 in-progress=63.81 | dev: reads=805 merged=0 kB/read=94.4 cold_near base 739.173 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 713.214 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 816.469 ms | shared hit=128633 read=9262 | Prefetch: avg=196.32 max=375 capacity=376 | I/O: count=45339 waits=371 size=1.00 in-progress=63.68 | dev: reads=803 merged=0 kB/read=94.7 ======== delay 2 ms, io_method=worker, eic 16 (control, --with-liburing builds) ======== file: results_2ms_worker_eic16.txt cold_near base 759.837 ms | shared hit=128671 read=9262 | | | dev: reads=693 merged=0 kB/read=109.8 cold_near v36 894.134 ms | shared hit=128566 read=9262 | Prefetch: avg=112.27 max=271 capacity=272 | I/O: count=21510 waits=544 size=1.00 in-progress=15.98 | dev: reads=812 merged=0 kB/read=93.7 cold_near v36 716.359 ms | shared hit=128569 read=9262 | Prefetch: avg=96.38 max=271 capacity=272 | I/O: count=24133 waits=486 size=1.00 in-progress=15.94 | dev: reads=777 merged=0 kB/read=97.9 cold_near base 686.676 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 693.308 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 803.587 ms | shared hit=128570 read=9262 | Prefetch: avg=96.29 max=271 capacity=272 | I/O: count=24499 waits=519 size=1.00 in-progress=15.96 | dev: reads=804 merged=0 kB/read=94.6 cold_near v36 801.003 ms | shared hit=128568 read=9262 | Prefetch: avg=101.34 max=271 capacity=272 | I/O: count=23110 waits=486 size=1.00 in-progress=15.93 | dev: reads=787 merged=0 kB/read=96.7 cold_near base 713.368 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 679.883 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 809.360 ms | shared hit=128565 read=9262 | Prefetch: avg=96.81 max=271 capacity=272 | I/O: count=24845 waits=518 size=1.00 in-progress=15.94 | dev: reads=808 merged=0 kB/read=94.1 cold_corr base 652.716 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 271.868 ms | shared read=9260 | Prefetch: avg=255.71 max=271 capacity=272 | I/O: count=514 waits=142 size=15.88 in-progress=15.46 | dev: reads=691 merged=0 kB/read=110.0 cold_corr v36 317.911 ms | shared read=9260 | Prefetch: avg=256.67 max=271 capacity=272 | I/O: count=514 waits=120 size=15.88 in-progress=15.51 | dev: reads=691 merged=0 kB/read=110.0 cold_corr base 634.490 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr base 656.403 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 342.476 ms | shared read=9260 | Prefetch: avg=255.58 max=271 capacity=272 | I/O: count=514 waits=148 size=15.88 in-progress=15.44 | dev: reads=691 merged=0 kB/read=109.9 cold_corr v36 303.390 ms | shared read=9260 | Prefetch: avg=255.74 max=271 capacity=272 | I/O: count=514 waits=173 size=15.88 in-progress=15.46 | dev: reads=691 merged=0 kB/read=110.0 cold_corr base 611.305 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr base 677.298 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 337.760 ms | shared read=9260 | Prefetch: avg=256.39 max=271 capacity=272 | I/O: count=514 waits=137 size=15.88 in-progress=15.49 | dev: reads=691 merged=0 kB/read=110.0 ======== delay 2 ms, io_method=io_uring, eic 16 ======== file: results_2ms_io_uring_eic16.txt cold_near base 608.865 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 680.972 ms | shared hit=127669 read=9262 | Prefetch: avg=32.68 max=41 capacity=272 | I/O: count=65087 waits=405 size=1.00 in-progress=15.97 | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 676.206 ms | shared hit=127674 read=9262 | Prefetch: avg=32.57 max=41 capacity=272 | I/O: count=64898 waits=411 size=1.00 in-progress=15.94 | dev: reads=690 merged=0 kB/read=110.2 cold_near base 624.405 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 780.401 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 703.659 ms | shared hit=127674 read=9262 | Prefetch: avg=32.57 max=41 capacity=272 | I/O: count=64898 waits=400 size=1.00 in-progress=15.94 | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 722.234 ms | shared hit=127669 read=9262 | Prefetch: avg=32.64 max=41 capacity=272 | I/O: count=65017 waits=401 size=1.00 in-progress=15.96 | dev: reads=689 merged=0 kB/read=110.2 cold_near base 712.393 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 697.989 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 665.212 ms | shared hit=127669 read=9262 | Prefetch: avg=32.64 max=41 capacity=272 | I/O: count=65017 waits=422 size=1.00 in-progress=15.96 | dev: reads=690 merged=0 kB/read=110.2 cold_corr base 719.615 ms | shared read=9260 | | | dev: reads=692 merged=0 kB/read=109.7 cold_corr v36 246.525 ms | shared read=9260 | Prefetch: avg=236.38 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=15.13 | dev: reads=691 merged=0 kB/read=110.0 cold_corr v36 197.097 ms | shared read=9260 | Prefetch: avg=238.77 max=256 capacity=272 | I/O: count=514 waits=9 size=15.88 in-progress=15.28 | dev: reads=690 merged=0 kB/read=110.2 cold_corr base 647.344 ms | shared read=9260 | | | dev: reads=692 merged=0 kB/read=109.8 cold_corr base 632.211 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 206.986 ms | shared read=9260 | Prefetch: avg=238.52 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=15.26 | dev: reads=690 merged=0 kB/read=110.2 cold_corr v36 197.856 ms | shared read=9260 | Prefetch: avg=240.59 max=256 capacity=272 | I/O: count=514 waits=8 size=15.88 in-progress=15.39 | dev: reads=693 merged=0 kB/read=109.7 cold_corr base 667.480 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr base 615.175 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 282.744 ms | shared read=9260 | Prefetch: avg=249.05 max=271 capacity=272 | I/O: count=514 waits=11 size=15.88 in-progress=15.24 | dev: reads=692 merged=0 kB/read=109.9 ======== delay 2 ms, io_method=io_uring, eic 64 ======== file: results_2ms_io_uring_eic64.txt cold_near base 678.754 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 741.750 ms | shared hit=128536 read=9262 | Prefetch: avg=80.71 max=115 capacity=376 | I/O: count=106625 waits=465 size=1.00 in-progress=63.80 | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 680.460 ms | shared hit=128536 read=9262 | Prefetch: avg=80.23 max=114 capacity=376 | I/O: count=106422 waits=416 size=1.00 in-progress=63.67 | dev: reads=690 merged=0 kB/read=110.2 cold_near base 686.557 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 817.741 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 760.274 ms | shared hit=128511 read=9262 | Prefetch: avg=80.54 max=113 capacity=376 | I/O: count=106530 waits=434 size=1.00 in-progress=63.77 | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 672.421 ms | shared hit=128513 read=9262 | Prefetch: avg=80.00 max=111 capacity=376 | I/O: count=106766 waits=443 size=1.00 in-progress=63.67 | dev: reads=690 merged=0 kB/read=110.2 cold_near base 665.140 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near base 725.470 ms | shared hit=128671 read=9262 | | | dev: reads=690 merged=0 kB/read=110.2 cold_near v36 730.184 ms | shared hit=128530 read=9262 | Prefetch: avg=80.41 max=113 capacity=376 | I/O: count=106357 waits=472 size=1.00 in-progress=63.69 | dev: reads=690 merged=0 kB/read=110.2 cold_corr base 649.543 ms | shared read=9260 | | | dev: reads=693 merged=0 kB/read=109.8 cold_corr v36 210.136 ms | shared read=9260 | Prefetch: avg=239.40 max=256 capacity=376 | I/O: count=514 waits=8 size=15.88 in-progress=15.32 | dev: reads=692 merged=0 kB/read=109.9 cold_corr v36 202.363 ms | shared read=9260 | Prefetch: avg=239.90 max=256 capacity=376 | I/O: count=514 waits=8 size=15.88 in-progress=15.35 | dev: reads=691 merged=0 kB/read=109.9 cold_corr base 673.980 ms | shared read=9260 | | | dev: reads=721 merged=0 kB/read=105.6 cold_corr base 638.536 ms | shared read=9260 | | | dev: reads=696 merged=0 kB/read=109.4 cold_corr v36 176.111 ms | shared read=9260 | Prefetch: avg=239.71 max=256 capacity=376 | I/O: count=514 waits=8 size=15.88 in-progress=15.34 | dev: reads=692 merged=0 kB/read=109.9 cold_corr v36 224.432 ms | shared read=9260 | Prefetch: avg=239.96 max=256 capacity=376 | I/O: count=514 waits=8 size=15.88 in-progress=15.35 | dev: reads=693 merged=0 kB/read=109.7 cold_corr base 656.058 ms | shared read=9260 | | | dev: reads=707 merged=0 kB/read=107.9 cold_corr base 708.272 ms | shared read=9260 | | | dev: reads=694 merged=0 kB/read=109.6 cold_corr v36 199.227 ms | shared read=9260 | Prefetch: avg=239.90 max=256 capacity=376 | I/O: count=514 waits=8 size=15.88 in-progress=15.35 | dev: reads=691 merged=0 kB/read=110.0