Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1240976
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() |
| Date | 2015-10-06 22:40 +0200 |
| Message-ID | <qgHbI-dA-9@gated-at.bofh.it> (permalink) |
| References | <qgD85-2O1-3@gated-at.bofh.it> <qgD85-2O1-5@gated-at.bofh.it> <qgDhM-2Zi-17@gated-at.bofh.it> <qgGIH-84P-27@gated-at.bofh.it> <qgGSm-8hZ-21@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Oct 06, 2015 at 01:19:15PM -0700, Paul E. McKenney wrote:
> On Tue, Oct 06, 2015 at 10:07:25PM +0200, Peter Zijlstra wrote:
> > On Tue, Oct 06, 2015 at 09:13:42AM -0700, Paul E. McKenney wrote:
> > > Currently, __srcu_read_lock() cannot be invoked from restricted
> > > environments because it contains calls to preempt_disable() and
> > > preempt_enable(), both of which can invoke lockdep, which is a bad
> > > idea in some restricted execution modes. This commit therefore moves
> > > the preempt_disable() and preempt_enable() from __srcu_read_lock()
> > > to srcu_read_lock(). It also inserts the preempt_disable() and
> > > preempt_enable() around the call to __srcu_read_lock() in do_exit().
> >
> > Did you not simply want to use: preempt_disable_notrace() ?
>
> I believe that tracing the preempt_disable() in srcu_read_lock() and
> srcu_read_unlock() is actually a good thing. Or am I missing your
> point?
Depends a bit on why we needed this change in the first place -- which,
going by the other branch of this thread, seems lost. However,
preempt_{dis,en}able_notrace() will not end up in any tracer/lockdep and
generate the minimum code that preserves the required semantics.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH tip/core/rcu 0/13] Miscellaneous fixes for 4.4 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
Re: [Kernel networking modules.] OSI levels 2 & 3, Assistance - If anyone knows anyone in the US. North West region "John D Allen, Leveridge Systems INC" <john.allen@leveridgesystems.com> - 2015-10-06 18:30 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Josh Triplett <josh@joshtriplett.org> - 2015-10-06 18:50 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:20 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:50 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 19:50 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Peter Zijlstra <peterz@infradead.org> - 2015-10-06 22:10 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 22:20 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Peter Zijlstra <peterz@infradead.org> - 2015-10-06 23:00 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 23:10 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers Peter Zijlstra <peterz@infradead.org> - 2015-10-07 09:30 +0200
Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 19:20 +0200
[PATCH tip/core/rcu 03/13] rcu: Use call_rcu_func_t to replace explicit type equivalents "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 01/13] sched: Export sched_setscheduler_nocheck "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 09/13] rcu: Correct comment for values of ->gp_state field "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 11/13] rculist: Make list_entry_rcu() use lockless_dereference() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 02/13] rcu: Use rcu_callback_t in call_rcu*() and friends "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 12/13] rcu: Remove deprecated rcu_lockdep_assert() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
[PATCH tip/core/rcu 06/13] rcu: Add online/offline info to stall warning message "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:20 +0200
Re: [PATCH tip/core/rcu 06/13] rcu: Add online/offline info to stall warning message Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:20 +0200
[PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:30 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:20 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 19:40 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:50 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 20:10 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() Peter Zijlstra <peterz@infradead.org> - 2015-10-06 22:10 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 22:20 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() Peter Zijlstra <peterz@infradead.org> - 2015-10-06 22:40 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 23:10 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() Peter Zijlstra <peterz@infradead.org> - 2015-10-07 09:30 +0200
Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-07 16:20 +0200
[PATCH tip/core/rcu 05/13] rcu: Eliminate panic when silly boot-time fanout specified "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:30 +0200
[PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 18:30 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:30 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 19:40 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:40 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() Peter Zijlstra <peterz@infradead.org> - 2015-10-06 22:30 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 23:10 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() Peter Zijlstra <peterz@infradead.org> - 2015-10-07 09:30 +0200
Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-07 16:30 +0200
Re: [PATCH tip/core/rcu 0/13] Miscellaneous fixes for 4.4 Josh Triplett <josh@joshtriplett.org> - 2015-10-06 19:30 +0200
Re: [PATCH tip/core/rcu 0/13] Miscellaneous fixes for 4.4 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-10-06 19:40 +0200
csiph-web