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* [PATCH tip/core/rcu 0/21] De-emphasize {smp_,}read_barrier_depends
@ 2017-12-01 19:50 Paul E. McKenney
  2017-12-01 19:50 ` [PATCH tip/core/rcu 01/21] doc: READ_ONCE() now implies smp_barrier_depends() Paul E. McKenney
                   ` (21 more replies)
  0 siblings, 22 replies; 60+ messages in thread
From: Paul E. McKenney @ 2017-12-01 19:50 UTC (permalink / raw)
  To: linux-kernel
  Cc: mingo, jiangshanlai, dipankar, akpm, mathieu.desnoyers, josh,
	tglx, peterz, rostedt, dhowells, edumazet, fweisbec, oleg

Hello!

Now that READ_ONCE() includes smp_read_barrier_depends(), almost nothing
else needs to, the exceptions being DEC Alpha architecture-specific
code and of course READ_ONCE() itself.  This series therefore removes
smp_read_barrier_depends() and read_barrier_depends() from elsewhere,
as they no longer have any effect.  Note that this patch series also
prohibits use of InfiniBand on DEC Alpha: (1) A poll of DEC Alpha
users revealed no use of InfiniBand and (2) It is not clear that
InfiniBand's memory ordering correctly handles DEC Alpha, even with the
smp_read_barrier_depends() invocations.

Note also that patch 4 moves to release-acquire ordering to ensure that
the name length is properly synchronized.  An alternative approach would
be to place the length in with the name, so that dependency ordering
would cover both the length and the name, but doing so seemed a bit
intrusive for this series.

							Thanx, Paul

------------------------------------------------------------------------

 Documentation/RCU/Design/Requirements/Requirements.html |    3 -
 Documentation/RCU/rcu_dereference.txt                   |    6 --
 Documentation/RCU/whatisRCU.txt                         |    3 -
 Documentation/circular-buffers.txt                      |    3 -
 Documentation/memory-barriers.txt                       |   18 ++++---
 arch/mn10300/kernel/mn10300-serial.c                    |    7 ++-
 drivers/dma/ioat/dma.c                                  |    2 
 drivers/infiniband/Kconfig                              |    1 
 drivers/infiniband/hw/hfi1/rc.c                         |    4 -
 drivers/infiniband/hw/hfi1/ruc.c                        |    1 
 drivers/infiniband/hw/hfi1/sdma.c                       |    1 
 drivers/infiniband/hw/hfi1/uc.c                         |    2 
 drivers/infiniband/hw/hfi1/ud.c                         |    2 
 drivers/infiniband/hw/qib/qib_rc.c                      |    3 -
 drivers/infiniband/hw/qib/qib_ruc.c                     |    1 
 drivers/infiniband/hw/qib/qib_uc.c                      |    2 
 drivers/infiniband/hw/qib/qib_ud.c                      |    2 
 drivers/infiniband/sw/rdmavt/qp.c                       |    1 
 drivers/net/ethernet/qlogic/qed/qed_spq.c               |    4 -
 drivers/vhost/vhost.c                                   |    7 ---
 fs/dcache.c                                             |   10 +---
 include/linux/genetlink.h                               |    3 -
 include/linux/netfilter/nfnetlink.h                     |    3 -
 include/linux/percpu-refcount.h                         |    6 +-
 include/linux/rcupdate.h                                |   23 ++++-----
 include/linux/rtnetlink.h                               |    3 -
 include/linux/seqlock.h                                 |    3 -
 kernel/events/uprobes.c                                 |   12 ++---
 kernel/locking/qspinlock.c                              |   12 ++---
 kernel/tracepoint.c                                     |    9 +--
 lib/assoc_array.c                                       |   37 +++++-----------
 lib/percpu-refcount.c                                   |    8 +--
 mm/ksm.c                                                |    9 ---
 net/ipv4/netfilter/arp_tables.c                         |    7 ---
 net/ipv4/netfilter/ip_tables.c                          |    7 ---
 net/ipv6/netfilter/ip6_tables.c                         |    7 ---
 scripts/checkpatch.pl                                   |    6 ++
 security/keys/keyring.c                                 |    7 ---
 38 files changed, 85 insertions(+), 160 deletions(-)

^ permalink raw reply	[flat|nested] 60+ messages in thread

end of thread, other threads:[~2017-12-05 23:40 UTC | newest]

Thread overview: 60+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-01 19:50 [PATCH tip/core/rcu 0/21] De-emphasize {smp_,}read_barrier_depends Paul E. McKenney
2017-12-01 19:50 ` [PATCH tip/core/rcu 01/21] doc: READ_ONCE() now implies smp_barrier_depends() Paul E. McKenney
2017-12-01 19:50 ` [PATCH tip/core/rcu 02/21] mn10300: READ_ONCE() now implies smp_read_barrier_depends() Paul E. McKenney
2017-12-01 19:50 ` [PATCH tip/core/rcu 03/21] drivers/net/ethernet/qlogic/qed: Fix __qed_spq_block() ordering Paul E. McKenney
2017-12-01 19:50 ` [PATCH tip/core/rcu 04/21] fs/dcache: Use release-acquire for name/length update Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 05/21] percpu: READ_ONCE() now implies smp_read_barrier_depends() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 06/21] rcu: Adjust read-side accessor comments for READ_ONCE() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 07/21] rtnetlink: Update now-misleading smp_read_barrier_depends() comment Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 08/21] seqlock: Remove now-redundant smp_read_barrier_depends() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 09/21] uprobes: " Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 10/21] locking: Remove smp_read_barrier_depends() from queued_spin_lock_slowpath() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 11/21] tracepoint: Remove smp_read_barrier_depends() from comment Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 12/21] lib/assoc_array: Remove smp_read_barrier_depends() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 13/21] mm/ksm: Remove now-redundant smp_read_barrier_depends() Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 14/21] netfilter: " Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 15/21] keyring: " Paul E. McKenney
2017-12-04  0:59   ` James Morris
2017-12-04 18:54     ` Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 16/21] drivers/infiniband: " Paul E. McKenney
2017-12-02  0:11   ` Jason Gunthorpe
2017-12-02  1:08     ` Paul E. McKenney
2017-12-05 15:08       ` Jason Gunthorpe
2017-12-05 20:06         ` Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 17/21] doc: De-emphasize smp_read_barrier_depends Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 18/21] genetlink: Remove smp_read_barrier_depends() from comment Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 19/21] netlink: " Paul E. McKenney
2017-12-01 19:51 ` [PATCH tip/core/rcu 20/21] checkpatch: Add warnings for {smp_,}read_barrier_depends() Paul E. McKenney
2017-12-01 20:14   ` Joe Perches
2017-12-01 21:44     ` Paul E. McKenney
2017-12-02  4:45       ` Joe Perches
2017-12-04 19:06         ` Paul E. McKenney
2017-12-04 19:12           ` Joe Perches
2017-12-01 19:51 ` [PATCH tip/core/rcu 21/21] drivers/vhost: Remove now-redundant read_barrier_depends() Paul E. McKenney
2017-12-05 18:31   ` Michael S. Tsirkin
2017-12-05 18:39     ` Peter Zijlstra
2017-12-05 18:57       ` Michael S. Tsirkin
2017-12-05 19:17         ` Peter Zijlstra
2017-12-05 19:24           ` Michael S. Tsirkin
2017-12-05 19:33             ` Paul E. McKenney
2017-12-05 19:51               ` Michael S. Tsirkin
2017-12-05 19:57                 ` Peter Zijlstra
2017-12-05 20:28                   ` Michael S. Tsirkin
2017-12-05 21:17                     ` Peter Zijlstra
2017-12-05 21:42                       ` Michael S. Tsirkin
2017-12-05 20:08                 ` Paul E. McKenney
2017-12-05 21:24                   ` Michael S. Tsirkin
2017-12-05 21:36                     ` Paul E. McKenney
2017-12-05 21:43                       ` Michael S. Tsirkin
2017-12-05 22:02                         ` Paul E. McKenney
2017-12-05 22:09                       ` Peter Zijlstra
2017-12-05 21:57                     ` Peter Zijlstra
2017-12-05 22:09                       ` Michael S. Tsirkin
2017-12-05 23:39                         ` Paul E. McKenney
2017-12-05 19:55             ` Peter Zijlstra
2017-12-04 15:38 ` [PATCH tip/core/rcu 01/21] doc: READ_ONCE() now implies smp_barrier_depends() David Howells
2017-12-04 18:52   ` Paul E. McKenney
2017-12-04 21:54     ` Peter Zijlstra
2017-12-04 22:15       ` Paul E. McKenney
2017-12-04 22:39     ` David Howells
2017-12-04 22:57       ` Peter Zijlstra

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