Re: [patch 09/14] fs: use RCU / seqlock logic for reverse and multi-step operaitons

From: Andi Kleen
Date: Mon Mar 30 2009 - 08:17:09 EST


npiggin@xxxxxxx writes:

> The remaining usages for dcache_lock is to allow atomic, multi-step read-side
> operations over the directory tree by excluding modifications to the tree.
> Also, to walk in the leaf->root direction in the tree where we don't have
> a natural d_lock ordering. This is the hardest bit.

General thoughts: is there a way to add a self testing infrastructure
to this. e.g. by having more sequence counts per object (only enabled
in the debug case, so it doesn't matter when cache line bounces) and lots of
checks?

I suppose that would lower the work needed of actually fixing this to
work significantly.

-Andi
--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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