From: Peter Zijlstra <peterz@infradead.org>
To: Bart Van Assche <bvanassche@acm.org>
Cc: mingo@redhat.com, tj@kernel.org, longman@redhat.com,
johannes.berg@intel.com, linux-kernel@vger.kernel.org,
Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [PATCH v5 07/15] locking/lockdep: Free lock classes that are no longer in use
Date: Thu, 10 Jan 2019 20:47:03 +0100 [thread overview]
Message-ID: <20190110194703.GE2861@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <1547148671.83374.54.camel@acm.org>
On Thu, Jan 10, 2019 at 11:31:11AM -0800, Bart Van Assche wrote:
> On Thu, 2019-01-10 at 16:28 +0100, Peter Zijlstra wrote:
> > On Mon, Dec 17, 2018 at 01:29:54PM -0800, Bart Van Assche wrote:
> > > +static bool inside_selftest(void)
> > > +{
> > > + return current == lockdep_selftest_task_struct;
> > > +}
> > > +void lockdep_free_key_range(void *start, unsigned long size)
> > > +{
> > > + init_data_structures_once();
> > > +
> > > + if (inside_selftest())
> > > + lockdep_free_key_range_imm(start, size);
> > > + else
> > > + lockdep_free_key_range_reg(start, size);
> > > }
> >
> > That is .... unfortunate. The whole reason that whole immediate thing
> > works at all is because there is no concurrency what so ever that early,
> > right?
> >
> > Should we maybe key off of: 'system_state == SYSTEM_BOOTING' instead?
>
> Hi Peter,
>
> I agree that it is unfortunate that the selftests require a different code
> path. I have not been able to find any way to avoid this. Using the test
> system_state == SYSTEM_BOOTING should work and will allow to remove the
> lockdep_selftest_task_struct variable. Do you want me to make that change?
I can do it; another approach is simply using the _imm (maybe renamed to
_selftest) functions directly, and getting rid of this dynamic choice.
I'm undecided as of yet.
next prev parent reply other threads:[~2019-01-10 19:47 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-17 21:29 [PATCH v5 00/15] locking/lockdep: Add support for dynamic keys Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 01/15] locking/lockdep: Fix required memory size reported if CONFIG_PROVE_LOCKING=n Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 02/15] locking/lockdep: Make zap_class() remove all matching lock order entries Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 03/15] locking/lockdep: Reorder struct lock_class members Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 04/15] locking/lockdep: Initialize the locks_before and locks_after lists earlier Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 05/15] locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock() Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 06/15] locking/lockdep: Make it easy to detect whether or not inside a selftest Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 07/15] locking/lockdep: Free lock classes that are no longer in use Bart Van Assche
2019-01-10 15:20 ` Peter Zijlstra
2019-01-10 15:45 ` Peter Zijlstra
2019-01-10 15:24 ` Peter Zijlstra
2019-01-10 18:51 ` Bart Van Assche
2019-01-10 19:44 ` Peter Zijlstra
2019-01-10 21:56 ` Bart Van Assche
2019-01-11 8:35 ` Peter Zijlstra
2019-02-13 0:42 ` Bart Van Assche
2019-01-10 15:28 ` Peter Zijlstra
2019-01-10 19:31 ` Bart Van Assche
2019-01-10 19:47 ` Peter Zijlstra [this message]
2018-12-17 21:29 ` [PATCH v5 08/15] locking/lockdep: Reuse list entries " Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 09/15] locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 10/15] locking/lockdep: Reuse lock chains that have been freed Bart Van Assche
2018-12-17 21:29 ` [PATCH v5 11/15] locking/lockdep: Check data structure consistency Bart Van Assche
2019-01-10 15:51 ` Peter Zijlstra
2019-01-10 15:55 ` Peter Zijlstra
2018-12-17 21:29 ` [PATCH v5 12/15] locking/lockdep: Verify whether lock objects are small enough to be used as class keys Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 13/15] locking/lockdep: Add support for dynamic keys Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 14/15] kernel/workqueue: Use dynamic lockdep keys for workqueues Bart Van Assche
2018-12-17 21:30 ` [PATCH v5 15/15] lockdep tests: Test dynamic key registration Bart Van Assche
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