From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Ming Lei <tom.leiming@gmail.com>
Cc: mingo@elte.hu, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org,
Linus Torvalds <torvalds@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [RESEND PATCH 0/11] kernel:lockdep:replace DFS with BFS
Date: Thu, 16 Jul 2009 11:54:22 +0200 [thread overview]
Message-ID: <1247738062.15471.96.camel@twins> (raw)
In-Reply-To: <d82e647a0907160012p4f4ee559q1a04be4cfbc4753c@mail.gmail.com>
On Thu, 2009-07-16 at 15:12 +0800, Ming Lei wrote:
> 2009/7/16 Peter Zijlstra <a.p.zijlstra@chello.nl>:
> >
> > I've asked several times to comment on the removal of that generation
> > count DaveM did. Is that a normal part of DFS, or was that an
> > optimization on top particular to this problem, can something similar be
> > done for BFS, etc.
>
> DFS uses generation count DaveM did to decide if a class is visted, and BFS
> uses bitmap to mark a class is visted or not and the extra efficiency loss is
>
> bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
>
> before staring each BFS.
>
> On most of ARCH, bimap_zero can be optimizied to only consume very few
> instructions,
> can't it?
>
> It seems bitmap is more easily used in BFS than generation count.
Ah, I so missed that, sorry about that.
I'll go over the patches one more time and push them out.
Thanks!
prev parent reply other threads:[~2009-07-16 9:54 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
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 [this message]
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