tree 626b659a6e2e44f3c6a65e1053eec6e108e61332
parent edaa5ddf3833669a25654d42c0fb653dfdd906df
parent 2116d708b0580c0048fc80b82ec4b53f4ddaa166
author Linus Torvalds <torvalds@linux-foundation.org> 1602533180 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1602533180 -0700
mergetag object 2116d708b0580c0048fc80b82ec4b53f4ddaa166
 type commit
 tag locking-core-2020-10-12
 tagger Ingo Molnar <mingo@kernel.org> 1602510223 +0200
 
 These are the locking updates for v5.10:
 
  - Add deadlock detection for recursive read-locks. The rationale is outlined
    in:
 
      224ec489d3cd: ("lockdep/Documention: Recursive read lock detection reasoning")
 
    The main deadlock pattern we want to detect is:
 
            TASK A:                 TASK B:
 
            read_lock(X);
                                    write_lock(X);
            read_lock_2(X);
 
  - Add "latch sequence counters" (seqcount_latch_t):
 
       A sequence counter variant where the counter even/odd value is used to
       switch between two copies of protected data. This allows the read path,
       typically NMIs, to safely interrupt the write side critical section.
 
    We utilize this new variant for sched-clock, and to make x86 TSC handling safer.
 
  - Other seqlock cleanups, fixes and enhancements
 
  - KCSAN updates
 
  - LKMM updates
 
  - Misc updates, cleanups and fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAl+EX6QRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1g3gxAAkg+Jy/tcdRxlxlEDOQPFy1mBqvFmulNA
 pGFPkB6dzqmAWF/NfOZSl4g/h/mqGYsq2V+PfK5E8Sq8DQ/yCmnLhjgVOHNUUliv
 x0WWfOysNgJdtdf69NLYJufIQhxhyI0dwFHHoHIsCdGdGqjh2DVevQFPFTBjdpOc
 BUZYo+u3gCaCdB6A2nmlcWYbEw8eVEHgv3qLG6dq46J0KJOV0HfliqJoU3EZqH+s
 977LvEIo+THfuYWMo/Jepwngbi0y36KeeukOAdwm9fK196htBHIUR+YPPrAe+FWD
 z+UXP5IS5XIw9V1sGLmUaC2m+6gpdW19jKBtlzPkxHXmJmsgiZdLLeytEh3WYey7
 nzfH+9Jd4NyyZKucLssYkOjf6P5BxGKCyJ9LXb7vlSthIhiDdFNx47oKtW4hxjOY
 jubsI3BP5c3G1sIBIjTS53XmOhJg+Z52FxTpQ33JswXn1wGidcHZiuNHZuU5q28p
 +tn8rGb2NGJFb4Sw/Vp0yTcqIpEXf+vweiQoaxm6tc9BWzcVzZntGnh0i3gFotx/
 VgKafN4+pgXgo6bwHbN2WBK2FGyvcXFaptfaOMZL48En82hJ1DI6EnBEYN+vuERQ
 JcCXg+iHeeVbxoou7q8NJxITkBmEL5xNBIugXRRqNSP3fXLxKjFuPYqT84/e7yZi
 elGTReYcq6g=
 =Iq51
 -----END PGP SIGNATURE-----

Merge tag 'locking-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "These are the locking updates for v5.10:

   - Add deadlock detection for recursive read-locks.

     The rationale is outlined in commit 224ec489d3cd ("lockdep/
     Documention: Recursive read lock detection reasoning")

     The main deadlock pattern we want to detect is:

           TASK A:                 TASK B:

           read_lock(X);
                                   write_lock(X);
           read_lock_2(X);

   - Add "latch sequence counters" (seqcount_latch_t):

     A sequence counter variant where the counter even/odd value is used
     to switch between two copies of protected data. This allows the
     read path, typically NMIs, to safely interrupt the write side
     critical section.

     We utilize this new variant for sched-clock, and to make x86 TSC
     handling safer.

   - Other seqlock cleanups, fixes and enhancements

   - KCSAN updates

   - LKMM updates

   - Misc updates, cleanups and fixes"

* tag 'locking-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables"
  lockdep: Fix lockdep recursion
  lockdep: Fix usage_traceoverflow
  locking/atomics: Check atomic-arch-fallback.h too
  locking/seqlock: Tweak DEFINE_SEQLOCK() kernel doc
  lockdep: Optimize the memory usage of circular queue
  seqlock: Unbreak lockdep
  seqlock: PREEMPT_RT: Do not starve seqlock_t writers
  seqlock: seqcount_LOCKNAME_t: Introduce PREEMPT_RT support
  seqlock: seqcount_t: Implement all read APIs as statement expressions
  seqlock: Use unique prefix for seqcount_t property accessors
  seqlock: seqcount_LOCKNAME_t: Standardize naming convention
  seqlock: seqcount latch APIs: Only allow seqcount_latch_t
  rbtree_latch: Use seqcount_latch_t
  x86/tsc: Use seqcount_latch_t
  timekeeping: Use seqcount_latch_t
  time/sched_clock: Use seqcount_latch_t
  seqlock: Introduce seqcount_latch_t
  mm/swap: Do not abuse the seqcount_t latching API
  time/sched_clock: Use raw_read_seqcount_latch() during suspend
  ...