Re: cleanup the walk_page_range interface

From: Steven Price <steven.price@arm.com>
To: Jason Gunthorpe <jgg@mellanox.com>,
	Christoph Hellwig <hch@infradead.org>
Cc: "Linus Torvalds" <torvalds@linux-foundation.org>,
	"Christoph Hellwig" <hch@lst.de>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Thomas Hellström" <thomas@shipmail.org>,
	"Jerome Glisse" <jglisse@redhat.com>,
	Linux-MM <linux-mm@kvack.org>,
	"Linux List Kernel Mailing" <linux-kernel@vger.kernel.org>
Subject: Re: cleanup the walk_page_range interface
Date: Fri, 23 Aug 2019 16:36:05 +0100	[thread overview]
Message-ID: <ad8179e2-f404-1e48-e366-fcd1f139a202@arm.com> (raw)
In-Reply-To: <20190823134308.GH12847@mellanox.com>

On 23/08/2019 14:43, Jason Gunthorpe wrote:
> On Thu, Aug 15, 2019 at 11:27:51PM -0700, Christoph Hellwig wrote:
>> On Thu, Aug 08, 2019 at 10:50:37AM -0700, Linus Torvalds wrote:
>>> On Thu, Aug 8, 2019 at 8:42 AM Christoph Hellwig <hch@lst.de> wrote:
>>>>
>>>> this series is based on a patch from Linus to split the callbacks
>>>> passed to walk_page_range and walk_page_vma into a separate structure
>>>> that can be marked const, with various cleanups from me on top.
>>>
>>> The whole series looks good to me. Ack.
>>>
>>>> Note that both Thomas and Steven have series touching this area pending,
>>>> and there are a couple consumer in flux too - the hmm tree already
>>>> conflicts with this series, and I have potential dma changes on top of
>>>> the consumers in Thomas and Steven's series, so we'll probably need a
>>>> git tree similar to the hmm one to synchronize these updates.
>>>
>>> I'd be willing to just merge this now, if that helps. The conversion
>>> is mechanical, and my only slight worry would be that at least for my
>>> original patch I didn't build-test the (few) non-x86
>>> architecture-specific cases. But I did end up looking at them fairly
>>> closely  (basically using some grep/sed scripts to see that the
>>> conversions I did matched the same patterns). And your changes look
>>> like obvious improvements too where any mistake would have been caught
>>> by the compiler.
>>>
>>> So I'm not all that worried from a functionality standpoint, and if
>>> this will help the next merge window, I'll happily pull now.
>>
>> So what is the plan forward?  Probably a little late for 5.3,
>> so queue it up in -mm for 5.4 and deal with the conflicts in at least
>> hmm?  Queue it up in the hmm tree even if it doesn't 100% fit?
> 
> Did we make a decision on this? Due to travel & LPC I'd like to
> finalize the hmm tree next week.

I was planning on rebasing my series on this and posting it for 5.4 - I
hadn't actually realised this hasn't been picked up yet. I haven't had
much time to look at this recently.

FWIW you can add for the series:

Acked-by: Steven Price <steven.price@arm.com>

Steve