Re: [PATCH 00/62] XArray November 2017 Edition

Dave Chinner
2017-11-23T01:34:05Z

On Wed, Nov 22, 2017 at 01:06:37PM -0800, Matthew Wilcox wrote:
> From: Matthew Wilcox <mawilcox@microsoft.com>
>
> I've lost count of the number of times I've posted the XArray before,
> so time for a new numbering scheme. Here're two earlier versions,
> https://lkml.org/lkml/2017/3/17/724
> https://lwn.net/Articles/715948/ (this one's more loquacious in its
> description of things that are better about the radix tree API than the
> XArray).
>
> This time around, I've gone for an approach of many small changes.
> Unfortunately, that means you get 62 moderate patches instead of dozens
> of big ones.

Where's the API documentation that tells things like constraints
about locking and lock-less lookups via RCU?

e.g. I notice in the XFS patches you seem to randomly strip out
rcu_read_lock/unlock() pairs that are currently around radix tree
lookup operations without explanation. Without documentation
describing how this stuff is supposed to work, review is somewhat
difficult...

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com