Greetings, While dusting off regression testing trees, I noticed a substantial pipe-test dent at 4.14, and bisected it to b956575bed91. Log below.
skew_tick=1 audit=0 nodelayacct cgroup_disable=memory nopti nospectre_v2 nospec_store_bypass_disable gov performance taskset 0xc pipe-test 1 4.4.134 2.125751 usecs/loop -- avg 2.138286 935.3 KHz 4.5.7 2.111431 usecs/loop -- avg 2.141415 934.0 KHz 4.6.7 2.060672 usecs/loop -- avg 2.059993 970.9 KHz 4.7.10 2.086366 usecs/loop -- avg 2.090943 956.5 KHz 4.8.17 2.008318 usecs/loop -- avg 2.005780 997.1 KHz + ~2.00-ish 1.000 4.9.104 1.989143 usecs/loop -- avg 2.010945 994.6 KHz 4.10.17 2.010789 usecs/loop -- avg 2.006868 996.6 KHz 4.11.12 2.032123 usecs/loop -- avg 2.037766 981.5 KHz - ~2.04-ish 1.015 1.000 4.12.14 2.055745 usecs/loop -- avg 2.065894 968.1 KHz 4.13.16 2.024978 usecs/loop -- avg 2.045250 977.9 KHz 4.14.47 2.234518 usecs/loop -- avg 2.227716 897.8 KHz -- >2.22 1.110 1.093 1.000 4.15.18 2.287815 usecs/loop -- avg 2.295858 871.1 KHz --- >2.28 1.144 1.126 1.030 4.16.13 2.286036 usecs/loop -- avg 2.279057 877.6 KHz 4.17.0.g88a8676 2.288231 usecs/loop -- avg 2.288917 873.8 KHz b956575bed91ecfb136a8300742ecbbf451471ab is the first bad commit commit b956575bed91ecfb136a8300742ecbbf451471ab Author: Andy Lutomirski <l...@kernel.org> Date: Mon Oct 9 09:50:49 2017 -0700 x86/mm: Flush more aggressively in lazy TLB mode git bisect start # good: [569dbb88e80deb68974ef6fdd6a13edb9d686261] Linux 4.13 git bisect good 569dbb88e80deb68974ef6fdd6a13edb9d686261 # bad: [57a3ca7835962109d94533465a75e8c716b26845] Linux 4.14.47 git bisect bad 57a3ca7835962109d94533465a75e8c716b26845 # good: [fbf4432ff71b7a25bef993a5312906946d27f446] Merge branch 'akpm' (patches from Andrew) git bisect good fbf4432ff71b7a25bef993a5312906946d27f446 # bad: [3fefc31843cfe2b5f072efe11ed9ccaf6a7a5092] Merge tag 'pm-final-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm git bisect bad 3fefc31843cfe2b5f072efe11ed9ccaf6a7a5092 # good: [8d93c7a4315711ea0f7a95ca353a89c4ed0763fb] Merge tag 'pci-v4.14-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci git bisect good 8d93c7a4315711ea0f7a95ca353a89c4ed0763fb # good: [0f380715e51f5ff418cfccb4cd0d4fe4c48c3241] Merge tag 'sound-4.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound git bisect good 0f380715e51f5ff418cfccb4cd0d4fe4c48c3241 # bad: [e5f468b3f23313994c5e6c356135f9b0d76bcb94] Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input git bisect bad e5f468b3f23313994c5e6c356135f9b0d76bcb94 # good: [3d7882769b5dc929690f96e0c318c29b97f51018] Merge tag 'devprop-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm git bisect good 3d7882769b5dc929690f96e0c318c29b97f51018 # bad: [ae7df8f985f1b0445366ae6f6324cd08a218526e] Merge tag 'char-misc-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc git bisect bad ae7df8f985f1b0445366ae6f6324cd08a218526e # good: [be1f16ba35d97aff4d85c0daba0a02da51b7c83c] Merge branch '4.14-fixes' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus git bisect good be1f16ba35d97aff4d85c0daba0a02da51b7c83c # good: [a339b351304d5e6b02c7cf8eed895d181e64bce0] Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good a339b351304d5e6b02c7cf8eed895d181e64bce0 # bad: [7a23c5abb930cefcef85df6dc0c8fb3e8961980c] Merge tag 'dmaengine-fix-4.14-rc5' of git://git.infradead.org/users/vkoul/slave-dma git bisect bad 7a23c5abb930cefcef85df6dc0c8fb3e8961980c # good: [ab7ff471aa5db670197070760f022622793da7e5] x86/hyperv: Fix hypercalls with extended CPU ranges for TLB flushing git bisect good ab7ff471aa5db670197070760f022622793da7e5 # bad: [1f161f67a272cc4f29f27934dd3f74cb657eb5c4] x86/microcode: Do the family check first git bisect bad 1f161f67a272cc4f29f27934dd3f74cb657eb5c4 # good: [cc6afe2240298049585e86b1ade85efc8a7f225d] x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on hypervisors git bisect good cc6afe2240298049585e86b1ade85efc8a7f225d # bad: [b956575bed91ecfb136a8300742ecbbf451471ab] x86/mm: Flush more aggressively in lazy TLB mode git bisect bad b956575bed91ecfb136a8300742ecbbf451471ab # good: [616dd5872e52493863b0202632703eebd51243dc] x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping git bisect good 616dd5872e52493863b0202632703eebd51243dc # first bad commit: [b956575bed91ecfb136a8300742ecbbf451471ab] x86/mm: Flush more aggressively in lazy TLB mode