From: Peter Zijlstra <peterz@infradead.org>
To: Byungchul Park <byungchul.park@lge.com>
Cc: mingo@kernel.org, tglx@linutronix.de, walken@google.com,
boqun.feng@gmail.com, kirill@shutemov.name,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
iamjoonsoo.kim@lge.com, akpm@linux-foundation.org,
npiggin@gmail.com
Subject: Re: [PATCH v4 07/15] lockdep: Implement crossrelease feature
Date: Tue, 17 Jan 2017 08:14:56 +0100 [thread overview]
Message-ID: <20170117071456.GK25813@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20170117020541.GF3326@X58A-UD3R>
On Tue, Jan 17, 2017 at 11:05:42AM +0900, Byungchul Park wrote:
> On Mon, Jan 16, 2017 at 04:10:01PM +0100, Peter Zijlstra wrote:
> > On Fri, Dec 09, 2016 at 02:12:03PM +0900, Byungchul Park wrote:
> > > @@ -155,6 +164,9 @@ struct lockdep_map {
> > > int cpu;
> > > unsigned long ip;
> > > #endif
> > > +#ifdef CONFIG_LOCKDEP_CROSSRELEASE
> > > + struct cross_lock *xlock;
> > > +#endif
> >
> > The use of this escapes me; why does the lockdep_map need a pointer to
> > this?
>
> Lockdep interfaces e.g. lock_acquire(), lock_release() and lock_commit()
> use lockdep_map as an arg, but crossrelease need to extract cross_lock
> instances from that.
> > Why not do something like:
> >
> > struct lockdep_map_cross {
> > struct lockdep_map map;
> > struct held_lock hlock;
> > }
Using a structure like that, you can pass lockdep_map_cross around just
fine, since the lockdep_map is the first member, so the pointers are
interchangeable. At worst we might need to munge a few typecasts.
But then the cross release code can simply cast to the bigger type and
have access to the extra data it knows to be there.
next prev parent reply other threads:[~2017-01-17 7:15 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-09 5:11 [PATCH v4 00/15] lockdep: Implement crossrelease feature Byungchul Park
2016-12-09 5:11 ` [PATCH v4 01/15] x86/dumpstack: Optimize save_stack_trace Byungchul Park
2016-12-09 5:11 ` [PATCH v4 02/15] x86/dumpstack: Add save_stack_trace()_fast() Byungchul Park
2016-12-09 5:11 ` [PATCH v4 03/15] lockdep: Refactor lookup_chain_cache() Byungchul Park
2016-12-09 5:12 ` [PATCH v4 04/15] lockdep: Add a function building a chain between two classes Byungchul Park
2017-01-10 21:00 ` Peter Zijlstra
2017-01-12 1:41 ` Byungchul Park
2016-12-09 5:12 ` [PATCH v4 05/15] lockdep: Make check_prev_add can use a separate stack_trace Byungchul Park
2017-01-12 16:16 ` Peter Zijlstra
2017-01-13 2:45 ` Byungchul Park
2017-01-13 4:09 ` [PATCH] lockdep: Make a stack_trace instance passed to check_prev_add as an arg Byungchul Park
2017-01-13 4:38 ` Byungchul Park
2017-01-13 10:11 ` [PATCH v4 05/15] lockdep: Make check_prev_add can use a separate stack_trace Byungchul Park
2017-01-13 10:17 ` [PATCH 1/2] lockdep: Refactor save_trace() Byungchul Park
2017-01-13 10:17 ` [PATCH 2/2] lockdep: Pass a callback arg to check_prev_add() to handle stack_trace Byungchul Park
2017-01-17 15:54 ` [PATCH v4 05/15] lockdep: Make check_prev_add can use a separate stack_trace Peter Zijlstra
2017-01-18 2:04 ` Byungchul Park
2017-01-18 15:10 ` Peter Zijlstra
2017-01-19 2:47 ` Byungchul Park
2016-12-09 5:12 ` [PATCH v4 06/15] lockdep: Make save_trace can skip stack tracing of the current Byungchul Park
2017-01-12 16:37 ` Peter Zijlstra
2017-01-13 0:18 ` Byungchul Park
2016-12-09 5:12 ` [PATCH v4 07/15] lockdep: Implement crossrelease feature Byungchul Park
2017-01-13 4:39 ` Lai Jiangshan
2017-01-13 5:02 ` Byungchul Park
2017-01-16 15:10 ` Peter Zijlstra
2017-01-17 2:05 ` Byungchul Park
2017-01-17 7:12 ` Peter Zijlstra
2017-01-17 7:49 ` Byungchul Park
2017-01-17 7:14 ` Peter Zijlstra [this message]
2017-01-17 7:45 ` Byungchul Park
2017-01-16 15:13 ` Peter Zijlstra
2017-01-17 2:33 ` Byungchul Park
2017-01-17 6:24 ` Boqun Feng
2017-01-17 7:43 ` Byungchul Park
2016-12-09 5:12 ` [PATCH v4 08/15] lockdep: Make crossrelease use save_stack_trace_fast() Byungchul Park
2016-12-09 5:12 ` [PATCH v4 09/15] lockdep: Make print_circular_bug() crosslock-aware Byungchul Park
2016-12-09 5:12 ` [PATCH v4 10/15] lockdep: Apply crossrelease to completion operation Byungchul Park
2016-12-09 5:12 ` [PATCH v4 11/15] pagemap.h: Remove trailing white space Byungchul Park
2016-12-09 5:12 ` [PATCH v4 12/15] lockdep: Apply crossrelease to PG_locked lock Byungchul Park
2016-12-09 5:12 ` [PATCH v4 13/15] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2016-12-09 5:12 ` [PATCH v4 14/15] lockdep: Move data used in CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2016-12-09 5:12 ` [PATCH v4 15/15] lockdep: Crossrelease feature documentation Byungchul Park
2017-01-10 20:08 ` Peter Zijlstra
2017-01-11 1:29 ` Byungchul Park
2017-01-18 6:42 ` Boqun Feng
2017-01-18 10:53 ` Byungchul Park
2017-01-18 11:03 ` Peter Zijlstra
2017-01-18 11:54 ` Byungchul Park
2017-01-18 12:07 ` Peter Zijlstra
2017-01-18 12:14 ` byungchul.park
2017-01-18 14:12 ` Peter Zijlstra
2017-01-19 1:54 ` Byungchul Park
2017-01-18 12:49 ` byungchul.park
2016-12-09 5:21 ` [FYI] Output of 'cat /proc/lockdep' after applying crossrelease Byungchul Park
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