From: Peter Zijlstra <peterz@infradead.org> To: Byungchul Park <byungchul.park@lge.com> Cc: Boqun Feng <boqun.feng@gmail.com>, mingo@kernel.org, tglx@linutronix.de, walken@google.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 15/15] lockdep: Crossrelease feature documentation Date: Wed, 18 Jan 2017 12:03:17 +0100 [thread overview] Message-ID: <20170118110317.GC6515@twins.programming.kicks-ass.net> (raw) In-Reply-To: <20170118105346.GL3326@X58A-UD3R> On Wed, Jan 18, 2017 at 07:53:47PM +0900, Byungchul Park wrote: > On Wed, Jan 18, 2017 at 02:42:30PM +0800, Boqun Feng wrote: > > On Fri, Dec 09, 2016 at 02:12:11PM +0900, Byungchul Park wrote: > > [...] > > > +Example 1: > > > + > > > + CONTEXT X CONTEXT Y > > > + --------- --------- > > > + mutext_lock A > > > + lock_page B > > > + lock_page B > > > + mutext_lock A /* DEADLOCK */ > > > > s/mutext_lock/mutex_lock > > Thank you. > > > > +Example 3: > > > + > > > + CONTEXT X CONTEXT Y > > > + --------- --------- > > > + mutex_lock A > > > + mutex_lock A > > > + mutex_unlock A > > > + wait_for_complete B /* DEADLOCK */ > > > > I think this part better be: > > > > CONTEXT X CONTEXT Y > > --------- --------- > > mutex_lock A > > mutex_lock A > > wait_for_complete B /* DEADLOCK */ > > mutex_unlock A > > > > , right? Because Y triggers DEADLOCK before X could run mutex_unlock(). > > There's no different between two examples. There is.. > No matter which one is chosen, mutex_lock A in CONTEXT X cannot be passed. But your version shows it does mutex_unlock() before CONTEXT Y does wait_for_completion(). The thing about these diagrams is that both columns are assumed to have the same timeline.
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From: Peter Zijlstra <peterz@infradead.org> To: Byungchul Park <byungchul.park@lge.com> Cc: Boqun Feng <boqun.feng@gmail.com>, mingo@kernel.org, tglx@linutronix.de, walken@google.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 15/15] lockdep: Crossrelease feature documentation Date: Wed, 18 Jan 2017 12:03:17 +0100 [thread overview] Message-ID: <20170118110317.GC6515@twins.programming.kicks-ass.net> (raw) In-Reply-To: <20170118105346.GL3326@X58A-UD3R> On Wed, Jan 18, 2017 at 07:53:47PM +0900, Byungchul Park wrote: > On Wed, Jan 18, 2017 at 02:42:30PM +0800, Boqun Feng wrote: > > On Fri, Dec 09, 2016 at 02:12:11PM +0900, Byungchul Park wrote: > > [...] > > > +Example 1: > > > + > > > + CONTEXT X CONTEXT Y > > > + --------- --------- > > > + mutext_lock A > > > + lock_page B > > > + lock_page B > > > + mutext_lock A /* DEADLOCK */ > > > > s/mutext_lock/mutex_lock > > Thank you. > > > > +Example 3: > > > + > > > + CONTEXT X CONTEXT Y > > > + --------- --------- > > > + mutex_lock A > > > + mutex_lock A > > > + mutex_unlock A > > > + wait_for_complete B /* DEADLOCK */ > > > > I think this part better be: > > > > CONTEXT X CONTEXT Y > > --------- --------- > > mutex_lock A > > mutex_lock A > > wait_for_complete B /* DEADLOCK */ > > mutex_unlock A > > > > , right? Because Y triggers DEADLOCK before X could run mutex_unlock(). > > There's no different between two examples. There is.. > No matter which one is chosen, mutex_lock A in CONTEXT X cannot be passed. But your version shows it does mutex_unlock() before CONTEXT Y does wait_for_completion(). The thing about these diagrams is that both columns are assumed to have the same timeline. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-01-18 11:03 UTC|newest] Thread overview: 104+ 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 ` Byungchul Park 2016-12-09 5:11 ` [PATCH v4 01/15] x86/dumpstack: Optimize save_stack_trace Byungchul Park 2016-12-09 5:11 ` 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 ` Byungchul Park 2016-12-09 5:11 ` [PATCH v4 03/15] lockdep: Refactor lookup_chain_cache() Byungchul Park 2016-12-09 5:11 ` Byungchul Park 2016-12-09 5:12 ` [PATCH v4 04/15] lockdep: Add a function building a chain between two classes Byungchul Park 2016-12-09 5:12 ` Byungchul Park 2017-01-10 21:00 ` Peter Zijlstra 2017-01-10 21:00 ` Peter Zijlstra 2017-01-12 1:41 ` Byungchul Park 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 2016-12-09 5:12 ` Byungchul Park 2017-01-12 16:16 ` Peter Zijlstra 2017-01-12 16:16 ` Peter Zijlstra 2017-01-13 2:45 ` Byungchul Park 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 10:11 ` 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 2017-01-17 15:54 ` Peter Zijlstra 2017-01-18 2:04 ` Byungchul Park 2017-01-18 2:04 ` Byungchul Park 2017-01-18 15:10 ` Peter Zijlstra 2017-01-18 15:10 ` Peter Zijlstra 2017-01-19 2:47 ` Byungchul Park 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 2016-12-09 5:12 ` Byungchul Park 2017-01-12 16:37 ` Peter Zijlstra 2017-01-12 16:37 ` Peter Zijlstra 2017-01-13 0:18 ` Byungchul Park 2017-01-13 0:18 ` Byungchul Park 2016-12-09 5:12 ` [PATCH v4 07/15] lockdep: Implement crossrelease feature Byungchul Park 2016-12-09 5:12 ` Byungchul Park 2017-01-13 4:39 ` Lai Jiangshan 2017-01-13 4:39 ` Lai Jiangshan 2017-01-13 5:02 ` Byungchul Park 2017-01-13 5:02 ` Byungchul Park 2017-01-16 15:10 ` Peter Zijlstra 2017-01-16 15:10 ` Peter Zijlstra 2017-01-17 2:05 ` Byungchul Park 2017-01-17 2:05 ` Byungchul Park 2017-01-17 7:12 ` Peter Zijlstra 2017-01-17 7:12 ` Peter Zijlstra 2017-01-17 7:49 ` Byungchul Park 2017-01-17 7:49 ` Byungchul Park 2017-01-17 7:14 ` Peter Zijlstra 2017-01-17 7:14 ` Peter Zijlstra 2017-01-17 7:45 ` Byungchul Park 2017-01-17 7:45 ` Byungchul Park 2017-01-16 15:13 ` Peter Zijlstra 2017-01-16 15:13 ` Peter Zijlstra 2017-01-17 2:33 ` Byungchul Park 2017-01-17 2:33 ` Byungchul Park 2017-01-17 6:24 ` Boqun Feng 2017-01-17 7:43 ` Byungchul Park 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 ` 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 ` Byungchul Park 2016-12-09 5:12 ` [PATCH v4 10/15] lockdep: Apply crossrelease to completion operation Byungchul Park 2016-12-09 5:12 ` Byungchul Park 2016-12-09 5:12 ` [PATCH v4 11/15] pagemap.h: Remove trailing white space Byungchul Park 2016-12-09 5:12 ` 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 ` 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 ` 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 ` Byungchul Park 2016-12-09 5:12 ` [PATCH v4 15/15] lockdep: Crossrelease feature documentation Byungchul Park 2016-12-09 5:12 ` Byungchul Park 2017-01-10 20:08 ` Peter Zijlstra 2017-01-10 20:08 ` Peter Zijlstra 2017-01-11 1:29 ` Byungchul Park 2017-01-11 1:29 ` Byungchul Park 2017-01-18 6:42 ` Boqun Feng 2017-01-18 10:53 ` Byungchul Park 2017-01-18 10:53 ` Byungchul Park 2017-01-18 11:03 ` Peter Zijlstra [this message] 2017-01-18 11:03 ` Peter Zijlstra 2017-01-18 11:54 ` Byungchul Park 2017-01-18 11:54 ` Byungchul Park 2017-01-18 12:07 ` Peter Zijlstra 2017-01-18 12:07 ` Peter Zijlstra 2017-01-18 12:14 ` byungchul.park 2017-01-18 12:14 ` byungchul.park 2017-01-18 14:12 ` Peter Zijlstra 2017-01-18 14:12 ` Peter Zijlstra 2017-01-19 1:54 ` Byungchul Park 2017-01-19 1:54 ` Byungchul Park 2017-01-18 12:49 ` 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 2016-12-09 5:21 ` Byungchul Park
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