Re: [RFC PATCH] of: overlay: update phandle cache on overlay apply and remove

From: Rob Herring
Date: Wed Jun 20 2018 - 14:23:28 EST


On Sun, Jun 17, 2018 at 10:03 AM, <frowand.list@xxxxxxxxx> wrote:
> From: Frank Rowand <frank.rowand@xxxxxxxx>
>
> A comment in the review of the patch adding the phandle cache said that
> the cache would have to be updated when modules are applied and removed.
> This patch implements the cache updates.
>
> Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
> Reported-by: Alan Tull <atull@xxxxxxxxxx>
> Suggested-by: Alan Tull <atull@xxxxxxxxxx>
> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
> ---
>
> Compiles for one configuration.
> NOT boot tested.
> Not run through my normal process to check for new warnings, etc.

I'm assuming you will resend a non-RFC version for me to apply.

I think it would be a bit better if callers didn't have to do free and
populate themselves, but just made an invalidate call (like a normal
cache) and re-populating the cache could happen on demand. Or if it
was done as a single call, you could just copy the old entries to the
new larger array. But maybe there would be a race condition in doing
that? In any case, all that could be a subsequent patch.

Rob