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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: tom.leiming@gmail.com
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mingo@elte.hu
Subject: Re: [RESEND PATCH 0/11] kernel:lockdep:replace DFS with BFS
Date: Mon, 13 Jul 2009 11:16:14 +0200	[thread overview]
Message-ID: <1247476574.7529.55.camel@twins> (raw)
In-Reply-To: <1246201486-7308-1-git-send-email-tom.leiming@gmail.com>

On Sun, 2009-06-28 at 23:04 +0800, tom.leiming@gmail.com wrote:
> Hi,Peter
> 
> Currently lockdep uses recursion DFS(depth-first search) algorithm to
> search target in checking lock circle(check_noncircular()),irq-safe
> -> irq-unsafe(check_irq_usage()) and irq inversion when adding a new
> lock dependency. This patches replace the current DFS with BFS, based on
> the following consideration:
> 
>     1,no loss of efficiency, no matter DFS or BFS, the running time
>     are O(V+E) (V is vertex count, and E is edge count of one
>     graph);

I'd still like to get some feedback on the loss of that generation count
optimization done by DaveM, I haven't had time to analyze the
ramifications of that.


  parent reply	other threads:[~2009-07-13  9:16 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-28 15:04 [RESEND PATCH 0/11] kernel:lockdep:replace DFS with BFS tom.leiming
2009-06-28 15:04 ` [RESEND PATCH 01/11] kernel:lockdep:print the shortest dependency chain if finding a circle tom.leiming
2009-06-28 15:04   ` [RESEND PATCH 02/11] kernel:lockdep:improve implementation of BFS tom.leiming
2009-06-28 15:04     ` [RESEND PATCH 03/11] kernel:lockdep: introduce match function to BFS tom.leiming
2009-06-28 15:04       ` [RESEND PATCH 04/11] kernel:lockdep:implement check_noncircular() by BFS tom.leiming
2009-06-28 15:04         ` [RESEND PATCH 05/11] kernel:lockdep:implement find_usage_*wards " tom.leiming
2009-06-28 15:04           ` [RESEND PATCH 06/11] kernel:lockdep:introduce print_shortest_lock_dependencies tom.leiming
2009-06-28 15:04             ` [RESEND PATCH 07/11] kernel:lockdep: implement lockdep_count_*ward_deps by BFS tom.leiming
2009-06-28 15:04               ` [RESEND PATCH 08/11] kernel:lockdep: update memory usage introduced " tom.leiming
2009-06-28 15:04                 ` [RESEND PATCH 09/11] kernel:lockdep:add statistics info for max bfs queue depth tom.leiming
2009-06-28 15:04                   ` [RESEND PATCH 10/11] BFS cleanup tom.leiming
2009-06-28 15:04                     ` [RESEND PATCH 11/11] kernel:lockdep:fix return value of check_usage*() tom.leiming
2009-07-18 14:24                     ` [tip:core/locking] lockdep: BFS cleanup tip-bot for Peter Zijlstra
2009-07-18 17:23                       ` Peter Zijlstra
2009-08-02 13:03                     ` tip-bot for Peter Zijlstra
2009-07-18 14:24                   ` [tip:core/locking] lockdep: Add statistics info for max bfs queue depth tip-bot for Ming Lei
2009-08-02 13:03                   ` tip-bot for Ming Lei
2009-07-18 14:24                 ` [tip:core/locking] lockdep: Update memory usage introduced by BFS tip-bot for Ming Lei
2009-07-18 17:23                   ` Peter Zijlstra
2009-08-02 13:02                 ` tip-bot for Ming Lei
2009-07-18 14:24               ` [tip:core/locking] lockdep: Implement lockdep_count_*ward_deps " tip-bot for Ming Lei
2009-08-02 13:02               ` tip-bot for Ming Lei
2009-07-18 14:24             ` [tip:core/locking] lockdep: Introduce print_shortest_lock_dependencies tip-bot for Ming Lei
2009-08-02 13:02             ` tip-bot for Ming Lei
2009-07-18 14:23           ` [tip:core/locking] lockdep: Implement find_usage_*wards by BFS tip-bot for Ming Lei
2009-08-02 13:02           ` tip-bot for Ming Lei
2009-07-13  8:02         ` [RESEND PATCH 04/11] kernel:lockdep:implement check_noncircular() " Dave Young
2009-07-13  8:08           ` Dave Young
2009-07-21  3:33             ` Ming Lei
2009-07-18 14:23         ` [tip:core/locking] lockdep: Implement " tip-bot for Ming Lei
2009-08-02 13:02         ` tip-bot for Ming Lei
2009-07-18 14:23       ` [tip:core/locking] lockdep: Introduce match function to BFS tip-bot for Ming Lei
2009-08-02 13:01       ` tip-bot for Ming Lei
2009-07-18 14:23     ` [tip:core/locking] lockdep: Improve implementation of BFS tip-bot for Ming Lei
2009-08-02 13:01     ` tip-bot for Ming Lei
2009-07-11 21:30   ` [RESEND PATCH 01/11] kernel:lockdep:print the shortest dependency chain if finding a circle Frederic Weisbecker
2009-07-12  2:42     ` Ming Lei
2009-07-13  7:01       ` Ingo Molnar
2009-07-13  9:14         ` Peter Zijlstra
2009-07-13 13:56           ` Ming Lei
2009-07-13 13:51         ` Ming Lei
2009-07-13  9:01   ` Dave Young
2009-07-18 14:23   ` [tip:core/locking] lockdep: Print " tip-bot for Ming Lei
2009-08-02 13:01   ` tip-bot for Ming Lei
2009-07-11  0:43 ` [RESEND PATCH 0/11] kernel:lockdep:replace DFS with BFS Frederic Weisbecker
2009-07-11  3:25   ` Ming Lei
2009-07-11 21:09     ` Frederic Weisbecker
2009-07-12  2:29       ` Ming Lei
2009-07-13  7:02         ` Ingo Molnar
2009-07-13  9:16 ` Peter Zijlstra [this message]
2009-07-16  4:39   ` Ming Lei
2009-07-16  5:22     ` Peter Zijlstra
2009-07-16  7:12       ` Ming Lei
2009-07-16  9:54         ` Peter Zijlstra

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