linux/include
Jason Gunthorpe f25a546e65 RDMA/odp: Use mmu_interval_notifier_insert()
Replace the internal interval tree based mmu notifier with the new common
mmu_interval_notifier_insert() API. This removes a lot of code and fixes a
deadlock that can be triggered in ODP:

 zap_page_range()
  mmu_notifier_invalidate_range_start()
   [..]
    ib_umem_notifier_invalidate_range_start()
       down_read(&per_mm->umem_rwsem)
  unmap_single_vma()
    [..]
      __split_huge_page_pmd()
        mmu_notifier_invalidate_range_start()
        [..]
           ib_umem_notifier_invalidate_range_start()
              down_read(&per_mm->umem_rwsem)   // DEADLOCK

        mmu_notifier_invalidate_range_end()
           up_read(&per_mm->umem_rwsem)
  mmu_notifier_invalidate_range_end()
     up_read(&per_mm->umem_rwsem)

The umem_rwsem is held across the range_start/end as the ODP algorithm for
invalidate_range_end cannot tolerate changes to the interval
tree. However, due to the nested invalidation regions the second
down_read() can deadlock if there are competing writers. The new core code
provides an alternative scheme to solve this problem.

Fixes: ca748c39ea ("RDMA/umem: Get rid of per_mm->notifier_count")
Link: https://lore.kernel.org/r/20191112202231.3856-6-jgg@ziepe.ca
Tested-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-11-23 19:56:44 -04:00
..
acpi cpufreq: Use per-policy frequency QoS 2019-10-21 02:05:21 +02:00
asm-generic Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
clocksource
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2019-09-27 19:37:27 -07:00
drm
dt-bindings Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
keys
kvm
linux mm/hmm: define the pre-processor related parts of hmm.h even if disabled 2019-11-23 19:56:44 -04:00
math-emu
media
misc
net net: reorder 'struct net' fields to avoid false sharing 2019-10-19 12:21:53 -07:00
pcmcia
ras
rdma RDMA/odp: Use mmu_interval_notifier_insert() 2019-11-23 19:56:44 -04:00
scsi SCSI fixes on 20191015 2019-10-15 12:19:08 -07:00
soc
sound ASoC: Fixes for v5.4 2019-10-21 14:05:26 +02:00
target
trace for-5.4-rc4-tag 2019-10-23 06:14:29 -04:00
uapi TTY/Serial driver fixes for 5.4-rc3 2019-10-12 15:42:19 -07:00
vdso
video
xen xen: fixes and cleanups for 5.4-rc2 2019-10-04 11:13:09 -07:00
Kbuild - New Drivers 2019-09-23 19:37:49 -07:00