git bisect start
# bad: [9e98c678c2d6ae3a17cb2de55d17f69dddaa231b] Linux 5.1-rc1
git bisect bad 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b
# good: [1c163f4c7b3f621efff9b28a47abb36f7378d783] Linux 5.0
git bisect good 1c163f4c7b3f621efff9b28a47abb36f7378d783
# good: [e266ca36da7de45b64b05698e98e04b578a88888] Merge tag 'staging-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
git bisect good e266ca36da7de45b64b05698e98e04b578a88888
# bad: [36011ddc78395b59a8a418c37f20bcc18828f1ef] Merge tag 'gfs2-5.1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
git bisect bad 36011ddc78395b59a8a418c37f20bcc18828f1ef
# good: [4b057e73f28f1df13b77b77a52094238ffdf8abd] Merge tag 'drm-misc-fixes-2019-02-22' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
git bisect good 4b057e73f28f1df13b77b77a52094238ffdf8abd
# good: [610cd4eadec4f97acd25d3108b0e50d1362b3319] Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good 610cd4eadec4f97acd25d3108b0e50d1362b3319
# good: [cf2e8c544cd3b33e9e403b7b72404c221bf888d1] Merge tag 'mfd-next-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
git bisect good cf2e8c544cd3b33e9e403b7b72404c221bf888d1
# bad: [80201fe175cbf7f3e372f53eba0a881a702ad926] Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block
git bisect bad 80201fe175cbf7f3e372f53eba0a881a702ad926
# good: [4221b807d1f73c03d22543416d303b60a5d1ef31] Merge tag 'for-5.1/libata-20190301' of git://git.kernel.dk/linux-block
git bisect good 4221b807d1f73c03d22543416d303b60a5d1ef31
# bad: [19d62f6d00972f957c94aba0975c14490cfed385] block: remove bvec_iter_rewind()
git bisect bad 19d62f6d00972f957c94aba0975c14490cfed385
# bad: [e8cf978dffb2c603340d4615eec2e5358c9df06d] bcache: fix indentation issue, remove tabs on a hunk of code
git bisect bad e8cf978dffb2c603340d4615eec2e5358c9df06d
# bad: [058fdecc6de7cdecbf4c59b851e80eb2d6c5295f] block, bfq: fix in-service-queue check for queue merging
git bisect bad 058fdecc6de7cdecbf4c59b851e80eb2d6c5295f
# good: [05c2f5c30b3ca2346a5bb7c74b0c9515d8f4fbd2] block, bfq: split function bfq_better_to_idle
git bisect good 05c2f5c30b3ca2346a5bb7c74b0c9515d8f4fbd2
# bad: [9dee8b3b057e1da26f85f1842f2aaf3bb200fb94] block, bfq: fix queue removal from weights tree
git bisect bad 9dee8b3b057e1da26f85f1842f2aaf3bb200fb94
# good: [530c4cbb3c62f9e42dbf39279fb346f2d2ab4dbb] block, bfq: unconditionally plug I/O in asymmetric scenarios
git bisect good 530c4cbb3c62f9e42dbf39279fb346f2d2ab4dbb
# good: [d87447d84fe194b0e4f5413b5344dc82cc100711] block, bfq: fix sequential rq detection in rate estimation
git bisect good d87447d84fe194b0e4f5413b5344dc82cc100711
# first bad commit: [9dee8b3b057e1da26f85f1842f2aaf3bb200fb94] block, bfq: fix queue removal from weights tree