I bisected again, and again it came back to that mount point change. This seems so bizarre.
$ git bisect log
# bad: [6d4f0a79e5a307b6fd3ee3cc5bbb2fcb701b09db] UBUNTU: Ubuntu-4.4.0-57.78
# good: [db5f146d309e70067dae57798c9ea679af835aa7] UBUNTU: Ubuntu-4.4.0-53.74
git bisect start 'Ubuntu-4.4.0-57.78' 'Ubuntu-4.4.0-53.74'
# bad: [02bf412367b827aa5be05a315088ef5fdcf267ca] dmaengine: at_xdmac: fix spurious flag status for mem2mem transfers
git bisect bad 02bf412367b827aa5be05a315088ef5fdcf267ca
# bad: [1e089050b800ba7d6ba1bf5814827e6cca301ad5] smc91x: avoid self-comparison warning
git bisect bad 1e089050b800ba7d6ba1bf5814827e6cca301ad5
# bad: [d7632bdaba3dd143eac3c80bb7e2b0f62259583d] xhci: use default USB_RESUME_TIMEOUT when resuming ports.
git bisect bad d7632bdaba3dd143eac3c80bb7e2b0f62259583d
# bad: [7942010de9a2fe39e72b84e628867f4ff29a70f2] libxfs: clean up _calc_dquots_per_chunk
git bisect bad 7942010de9a2fe39e72b84e628867f4ff29a70f2
# good: [9d2524b0bdeb57f80d0279f6695a833606ad0597] UBUNTU: SAUCE: Bluetooth: decrease refcount after use
git bisect good 9d2524b0bdeb57f80d0279f6695a833606ad0597
# bad: [fd4b5fa6e3487d15ede746f92601af008b2abbc0] mnt: Add a per mount namespace limit on the number of mounts
git bisect bad fd4b5fa6e3487d15ede746f92601af008b2abbc0
# good: [f2109fe47ceb77647ef7d4f545efeba43d06fb64] videobuf2-v4l2: Verify planes array in buffer dequeueing
git bisect good f2109fe47ceb77647ef7d4f545efeba43d06fb64
# good: [d5d9494d2092a7e571dee635ca254075912355c1] thinkpad_acpi: Add support for HKEY version 0x200
git bisect good d5d9494d2092a7e571dee635ca254075912355c1
# first bad commit: [fd4b5fa6e3487d15ede746f92601af008b2abbc0] mnt: Add a per mount namespace limit on the number of mounts
I bisected again, and again it came back to that mount point change. This seems so bizarre.
$ git bisect log b6fd3ee3cc5bbb2 fcb701b09db] UBUNTU: Ubuntu-4.4.0-57.78 067dae57798c9ea 679af835aa7] UBUNTU: Ubuntu-4.4.0-53.74 4.4.0-57. 78' 'Ubuntu- 4.4.0-53. 74' aa5be05a315088e f5fdcf267ca] dmaengine: at_xdmac: fix spurious flag status for mem2mem transfers a5be05a315088ef 5fdcf267ca 7d6ba1bf5814827 e6cca301ad5] smc91x: avoid self-comparison warning d6ba1bf5814827e 6cca301ad5 43eac3c80bb7e2b 0f62259583d] xhci: use default USB_RESUME_TIMEOUT when resuming ports. 3eac3c80bb7e2b0 f62259583d 39e72b84e628867 f4ff29a70f2] libxfs: clean up _calc_dquots_ per_chunk 9e72b84e628867f 4ff29a70f2 f80d0279f6695a8 33606ad0597] UBUNTU: SAUCE: Bluetooth: decrease refcount after use 80d0279f6695a83 3606ad0597 15ede746f92601a f008b2abbc0] mnt: Add a per mount namespace limit on the number of mounts 5ede746f92601af 008b2abbc0 647ef7d4f545efe ba43d06fb64] videobuf2-v4l2: Verify planes array in buffer dequeueing 47ef7d4f545efeb a43d06fb64 e571dee635ca254 075912355c1] thinkpad_acpi: Add support for HKEY version 0x200 571dee635ca2540 75912355c1 15ede746f92601a f008b2abbc0] mnt: Add a per mount namespace limit on the number of mounts
# bad: [6d4f0a79e5a307
# good: [db5f146d309e70
git bisect start 'Ubuntu-
# bad: [02bf412367b827
git bisect bad 02bf412367b827a
# bad: [1e089050b800ba
git bisect bad 1e089050b800ba7
# bad: [d7632bdaba3dd1
git bisect bad d7632bdaba3dd14
# bad: [7942010de9a2fe
git bisect bad 7942010de9a2fe3
# good: [9d2524b0bdeb57
git bisect good 9d2524b0bdeb57f
# bad: [fd4b5fa6e3487d
git bisect bad fd4b5fa6e3487d1
# good: [f2109fe47ceb77
git bisect good f2109fe47ceb776
# good: [d5d9494d2092a7
git bisect good d5d9494d2092a7e
# first bad commit: [fd4b5fa6e3487d