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SubjectRe: [tip:core/locking 1/3] lockdep:reintroduce generation count to make BFS faster
2009/7/22 Peter Zijlstra <>:
> On Wed, 2009-07-22 at 20:58 +0800, wrote:
>> From: Ming Lei <>
>> We still can apply DaveM's generation count optimization to
>> BFS, so reintroduce it.
> Please elaborate, changelogs are important.

Sorry, I'll resend the patches and provide a elaborate changlogs.

> You fail to explain why it still applies and what the gains are.
> (I can guess, but you explaining makes sure we're on the same page)

1), avoid to allocate the bfs_accessed array;

2), remove the
bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
in each BFS, which is a little time consuming since
is very large.(16384UL)

Lei Ming

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