From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux MM <linux-mm@kvack.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH] mm/nvdimm: Use correct alignment when looking at first pfn from a region
Date: Mon, 27 May 2019 15:05:40 +0530 [thread overview]
Message-ID: <87k1ecutn7.fsf@linux.ibm.com> (raw)
In-Reply-To: <925e41ad-cc57-bc03-a2b6-6913c9e98abf@linux.ibm.com>
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> On 5/14/19 9:59 AM, Dan Williams wrote:
>> On Mon, May 13, 2019 at 7:55 PM Aneesh Kumar K.V
>> <aneesh.kumar@linux.ibm.com> wrote:
>>>
>>> We already add the start_pad to the resource->start but fails to section
>>> align the start. This make sure with altmap we compute the right first
>>> pfn when start_pad is zero and we are doing an align down of start address.
>>>
>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>> ---
>>> kernel/memremap.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/kernel/memremap.c b/kernel/memremap.c
>>> index a856cb5ff192..23d77b60e728 100644
>>> --- a/kernel/memremap.c
>>> +++ b/kernel/memremap.c
>>> @@ -59,9 +59,9 @@ static unsigned long pfn_first(struct dev_pagemap *pgmap)
>>> {
>>> const struct resource *res = &pgmap->res;
>>> struct vmem_altmap *altmap = &pgmap->altmap;
>>> - unsigned long pfn;
>>> + unsigned long pfn = PHYS_PFN(res->start);
>>>
>>> - pfn = res->start >> PAGE_SHIFT;
>>> + pfn = SECTION_ALIGN_DOWN(pfn);
>>
>> This does not seem right to me it breaks the assumptions of where the
>> first expected valid pfn occurs in the passed in range.
>>
>
> How do we define the first valid pfn? Isn't that at pfn_sb->dataoff ?
for altmap the pfn_first should be
pfn_first = altmap->base_pfn + vmem_altmap_offset(altmap);
?
-aneesh
prev parent reply other threads:[~2019-05-27 9:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-14 2:55 [PATCH] mm/nvdimm: Use correct alignment when looking at first pfn from a region Aneesh Kumar K.V
2019-05-14 4:29 ` Dan Williams
2019-05-14 4:41 ` Aneesh Kumar K.V
2019-05-27 9:35 ` Aneesh Kumar K.V [this message]
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=87k1ecutn7.fsf@linux.ibm.com \
--to=aneesh.kumar@linux.ibm.com \
--cc=dan.j.williams@intel.com \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=linuxppc-dev@lists.ozlabs.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).