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Groups > linux.kernel > #1680474
| From | "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions |
| Date | 2017-07-03 18:20 +0200 |
| Message-ID | <tZceT-3TE-43@gated-at.bofh.it> (permalink) |
| References | (2 earlier) <tY0fL-3yd-15@gated-at.bofh.it> <tY3x0-5xi-25@gated-at.bofh.it> <tY402-5YH-21@gated-at.bofh.it> <tYcqB-2Lm-5@gated-at.bofh.it> <tZ9qF-1XI-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Jul 03, 2017 at 02:15:14PM +0100, Will Deacon wrote: > On Fri, Jun 30, 2017 at 03:18:40PM -0700, Paul E. McKenney wrote: > > On Fri, Jun 30, 2017 at 02:13:39PM +0100, Will Deacon wrote: > > > On Fri, Jun 30, 2017 at 05:38:15AM -0700, Paul E. McKenney wrote: > > > > I also need to check all uses of spin_is_locked(). There might no > > > > longer be any that rely on any particular ordering... > > > > > > Right. I think we're looking for the "insane case" as per 38b850a73034 > > > (which was apparently used by ipc/sem.c at the time, but no longer). > > > > > > There's a usage in kernel/debug/debug_core.c, but it doesn't fill me with > > > joy. > > > > That is indeed an interesting one... But my first round will be what > > semantics the implementations seem to provide: > > > > Acquire courtesy of TSO: s390, sparc, x86. > > Acquire: ia64 (in reality fully ordered). > > Control dependency: alpha, arc, arm, blackfin, hexagon, m32r, mn10300, tile, > > xtensa. > > Control dependency plus leading full barrier: arm64, powerpc. > > UP-only: c6x, cris, frv, h8300, m68k, microblaze nios2, openrisc, um, unicore32. > > > > Special cases: > > metag: Acquire if !CONFIG_METAG_SMP_WRITE_REORDERING. > > Otherwise control dependency? > > mips: Control dependency, acquire if CONFIG_CPU_CAVIUM_OCTEON. > > parisc: Acquire courtesy of TSO, but why barrier in smp_load_acquire? > > sh: Acquire if one of SH4A, SH5, or J2, otherwise acquire? UP-only? > > > > Are these correct, or am I missing something with any of them? > > That looks about right but, at least on ARM, I think we have to consider > the semantics of spin_is_locked with respect to the other spin_* functions, > rather than in isolation. > > For example, ARM only has a control dependency, but spin_lock has a trailing > smp_mb() and spin_unlock has both leading and trailing smp_mb(). Agreed, and my next step is to look at spin_lock() followed by spin_is_locked(), not necessarily the same lock. Thanx, Paul
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[PATCH RFC 0/26] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:00 +0200
[PATCH RFC 13/26] blackfin: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Will Deacon <will.deacon@arm.com> - 2017-06-30 11:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 14:50 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Will Deacon <will.deacon@arm.com> - 2017-06-30 15:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-01 00:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Will Deacon <will.deacon@arm.com> - 2017-07-03 15:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-03 18:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Linus Torvalds <torvalds@linux-foundation.org> - 2017-07-03 18:50 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Will Deacon <will.deacon@arm.com> - 2017-07-03 19:20 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-04 00:40 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions Linus Torvalds <torvalds@linux-foundation.org> - 2017-07-04 01:00 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-04 02:50 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-04 03:00 +0200
Re: [PATCH RFC 08/26] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-03 23:20 +0200
[PATCH RFC 23/26] sh: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 16/26] m32r: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 21/26] powerpc: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
Re: [PATCH RFC 21/26] powerpc: Remove spin_unlock_wait() arch-specific definitions Boqun Feng <boqun.feng@gmail.com> - 2017-07-02 06:00 +0200
Re: [PATCH RFC 21/26] powerpc: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 02:00 +0200
[PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
Re: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-30 02:10 +0200
Re: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-30 02:20 +0200
Re: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:30 +0200
Re: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
Re: [PATCH RFC 25/26] tile: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
[PATCH RFC 18/26] mips: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 19/26] mn10300: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 20/26] parisc: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 15/26] ia64: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 11/26] arm: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 22/26] s390: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 01/26] netfilter: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
Re: [PATCH RFC 01/26] netfilter: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-02 04:10 +0200
[PATCH RFC 04/26] completion: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 07/26] drivers/ata: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 14/26] hexagon: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 09/26] alpha: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 24/26] sparc: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 26/26] xtensa: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:10 +0200
[PATCH RFC 03/26] sched: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
Re: [PATCH RFC 03/26] sched: Replace spin_unlock_wait() with lock/unlock pair Arnd Bergmann <arnd@arndb.de> - 2017-06-30 12:40 +0200
Re: [PATCH RFC 03/26] sched: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 14:40 +0200
[PATCH RFC 05/26] exit: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
[PATCH RFC 12/26] arm64: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
Re: [PATCH RFC 12/26] arm64: Remove spin_unlock_wait() arch-specific definitions Will Deacon <will.deacon@arm.com> - 2017-06-30 11:30 +0200
Re: [PATCH RFC 12/26] arm64: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 19:40 +0200
[PATCH RFC 10/26] arc: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
[PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 02:20 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair Oleg Nesterov <oleg@redhat.com> - 2017-06-30 13:10 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 15:00 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair Oleg Nesterov <oleg@redhat.com> - 2017-06-30 17:30 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 18:20 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 19:30 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair Oleg Nesterov <oleg@redhat.com> - 2017-06-30 21:30 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair Alan Stern <stern@rowland.harvard.edu> - 2017-06-30 22:00 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 22:10 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 22:10 +0200
Re: [PATCH RFC 02/26] task_work: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-06-30 22:20 +0200
Re: [PATCH RFC 06/26] ipc: Replace spin_unlock_wait() with lock/unlock pair Manfred Spraul <manfred@colorfullife.com> - 2017-07-01 21:30 +0200
Re: [PATCH RFC 06/26] ipc: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-02 05:20 +0200
[PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 01:40 +0200
[PATCH v2 9/9] arch: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 01:40 +0200
RE: [PATCH v2 0/9] Remove spin_unlock_wait() David Laight <David.Laight@ACULAB.COM> - 2017-07-06 16:20 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 17:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-06 18:20 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 18:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-06 18:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 19:10 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Alan Stern <stern@rowland.harvard.edu> - 2017-07-06 18:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-06 19:00 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Alan Stern <stern@rowland.harvard.edu> - 2017-07-06 21:40 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-06 18:10 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 18:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-06 19:00 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Will Deacon <will.deacon@arm.com> - 2017-07-06 19:10 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 19:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-06 19:20 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-07 10:40 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-07 10:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-07 12:40 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Peter Zijlstra <peterz@infradead.org> - 2017-07-07 13:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-07 16:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-08 10:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-08 13:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Manfred Spraul <manfred@colorfullife.com> - 2017-07-07 19:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-08 10:40 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-08 13:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-08 14:40 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-08 16:50 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Alan Stern <stern@rowland.harvard.edu> - 2017-07-08 18:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Manfred Spraul <manfred@colorfullife.com> - 2017-07-10 19:30 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-07 10:10 +0200
Re: [PATCH v2 0/9] Remove spin_unlock_wait() Ingo Molnar <mingo@kernel.org> - 2017-07-07 11:40 +0200
[PATCH v3 0/9] Remove spin_unlock_wait() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-07 21:30 +0200
[PATCH v3 9/9] arch: Remove spin_unlock_wait() arch-specific definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-07 21:40 +0200
[PATCH v3 5/9] exit: Replace spin_unlock_wait() with lock/unlock pair "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-07 21:40 +0200
[PATCH v3 8/9] locking: Remove spin_unlock_wait() generic definitions "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-07 21:40 +0200
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