From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Will Deacon <will@kernel.org>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
"David Hildenbrand" <david@redhat.com>,
"Catalin Marinas" <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org,
"Mike Rapoport" <rppt@linux.ibm.com>,
linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
"James Morse" <james.morse@arm.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Robin Murphy" <robin.murphy@arm.com>,
"Ard Biesheuvel" <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH V2 1/2] arm64/mm: Fix pfn_valid() for ZONE_DEVICE based memory
Date: Thu, 11 Feb 2021 17:40:35 +0530 [thread overview]
Message-ID: <23e5eb93-a39c-c68e-eac1-c5ccf9036079@arm.com> (raw)
In-Reply-To: <20210211115354.GB29894@willie-the-truck>
On 2/11/21 5:23 PM, Will Deacon wrote:
> On Fri, Feb 05, 2021 at 06:55:53PM +0000, Will Deacon wrote:
>> On Wed, Feb 03, 2021 at 09:20:39AM +0530, Anshuman Khandual wrote:
>>> On 2/2/21 6:26 PM, David Hildenbrand wrote:
>>>> On 02.02.21 13:51, Will Deacon wrote:
>>>>> On Tue, Feb 02, 2021 at 01:39:29PM +0100, David Hildenbrand wrote:
>>>>>> As I expressed already, long term we should really get rid of the arm64
>>>>>> variant and rather special-case the generic one. Then we won't go out of
>>>>>> sync - just as it happened with ZONE_DEVICE handling here.
>>>>>
>>>>> Why does this have to be long term? This ZONE_DEVICE stuff could be the
>>>>> carrot on the stick :)
>>>>
>>>> Yes, I suggested to do it now, but Anshuman convinced me that doing a
>>>> simple fix upfront might be cleaner --- for example when it comes to
>>>> backporting :)
>>>
>>> Right. The current pfn_valid() breaks for ZONE_DEVICE memory and this fixes
>>> the problem in the present context which can be easily backported if required.
>>>
>>> Changing or rather overhauling the generic code with new configs as proposed
>>> earlier (which I am planning to work on subsequently) would definitely be an
>>> improvement for the current pfn_valid() situation in terms of maintainability
>>> but then it should not stop us from fixing the problem now.
>>
>> Alright, I've mulled this over a bit. I don't agree that this patch helps
>> with maintainability (quite the opposite, in fact), but perfection is the
>> enemy of the good so I'll queue the series for 5.12. However, I'll revert
>> the changes at the first sign of a problem, so please do work towards a
>> generic solution which can replace this in the medium term.
>
> ... and dropped. These patches appear to be responsible for a boot
> regression reported by CKI:
Ahh, boot regression ? These patches only change the behaviour
for non boot memory only.
>
> https://lore.kernel.org/r/cki.8D1CB60FEC.K6NJMEFQPV@redhat.com
Will look into the logs and see if there is something pointing to
the problem.
next prev parent reply other threads:[~2021-02-11 12:10 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 4:11 [PATCH V2 0/2] arm64/mm: Fix pfn_valid() for ZONE_DEVICE based memory Anshuman Khandual
2021-02-02 4:11 ` [PATCH V2 1/2] " Anshuman Khandual
2021-02-02 12:32 ` Will Deacon
2021-02-02 12:35 ` Will Deacon
2021-02-02 12:39 ` David Hildenbrand
2021-02-02 12:51 ` Will Deacon
2021-02-02 12:56 ` David Hildenbrand
2021-02-03 3:50 ` Anshuman Khandual
2021-02-05 18:55 ` Will Deacon
2021-02-11 11:53 ` Will Deacon
2021-02-11 12:10 ` Anshuman Khandual [this message]
2021-02-11 12:21 ` Will Deacon
2021-02-11 12:35 ` David Hildenbrand
2021-03-03 19:04 ` Catalin Marinas
2021-03-03 19:24 ` David Hildenbrand
2021-03-03 21:24 ` Will Deacon
2021-03-04 3:31 ` Anshuman Khandual
2021-03-04 8:12 ` David Hildenbrand
2021-03-04 9:36 ` Will Deacon
2021-03-05 4:22 ` Anshuman Khandual
2021-02-02 4:11 ` [PATCH V2 2/2] arm64/mm: Reorganize pfn_valid() Anshuman Khandual
2021-02-02 8:26 ` David Hildenbrand
2021-02-05 18:52 ` [PATCH V2 0/2] arm64/mm: Fix pfn_valid() for ZONE_DEVICE based memory Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=23e5eb93-a39c-c68e-eac1-c5ccf9036079@arm.com \
--to=anshuman.khandual@arm.com \
--cc=ardb@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=james.morse@arm.com \
--cc=jglisse@redhat.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mark.rutland@arm.com \
--cc=robin.murphy@arm.com \
--cc=rppt@linux.ibm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).