Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Qian Cai <cai@lca.pw>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Oscar Salvador <osalvador@suse.de>, Linux MM <linux-mm@kvack.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -next] mm/hotplug: skip bad PFNs from pfn_to_online_page()
Date: Fri, 14 Jun 2019 10:59:25 -0400
Message-ID: <1560524365.5154.21.camel@lca.pw> (raw)
In-Reply-To: <87lfy4ilvj.fsf@linux.ibm.com>

On Fri, 2019-06-14 at 14:28 +0530, Aneesh Kumar K.V wrote:
> Qian Cai <cai@lca.pw> writes:
> 
> 
> > 1) offline is busted [1]. It looks like test_pages_in_a_zone() missed the
> > same
> > pfn_section_valid() check.
> > 
> > 2) powerpc booting is generating endless warnings [2]. In
> > vmemmap_populated() at
> > arch/powerpc/mm/init_64.c, I tried to change PAGES_PER_SECTION to
> > PAGES_PER_SUBSECTION, but it alone seems not enough.
> > 
> 
> Can you check with this change on ppc64.  I haven't reviewed this series yet.
> I did limited testing with change . Before merging this I need to go
> through the full series again. The vmemmap poplulate on ppc64 needs to
> handle two translation mode (hash and radix). With respect to vmemap
> hash doesn't setup a translation in the linux page table. Hence we need
> to make sure we don't try to setup a mapping for a range which is
> arleady convered by an existing mapping.

It works fine.

> 
> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
> index a4e17a979e45..15c342f0a543 100644
> --- a/arch/powerpc/mm/init_64.c
> +++ b/arch/powerpc/mm/init_64.c
> @@ -88,16 +88,23 @@ static unsigned long __meminit
> vmemmap_section_start(unsigned long page)
>   * which overlaps this vmemmap page is initialised then this page is
>   * initialised already.
>   */
> -static int __meminit vmemmap_populated(unsigned long start, int page_size)
> +static bool __meminit vmemmap_populated(unsigned long start, int page_size)
>  {
>  	unsigned long end = start + page_size;
>  	start = (unsigned long)(pfn_to_page(vmemmap_section_start(start)));
>  
> -	for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct
> page)))
> -		if (pfn_valid(page_to_pfn((struct page *)start)))
> -			return 1;
> +	for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct
> page))) {
>  
> -	return 0;
> +		struct mem_section *ms;
> +		unsigned long pfn = page_to_pfn((struct page *)start);
> +
> +		if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
> +			return 0;
> +		ms = __nr_to_section(pfn_to_section_nr(pfn));
> +		if (valid_section(ms))
> +			return true;
> +	}
> +	return false;
>  }
>  
>  /*
> 


  reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-12 19:15 Qian Cai
2019-06-12 19:37 ` Dan Williams
2019-06-12 19:38   ` Dan Williams
2019-06-12 21:47     ` Qian Cai
2019-06-12 21:52       ` Dan Williams
2019-06-12 23:13         ` Dan Williams
2019-06-13  0:06       ` Dan Williams
2019-06-14  8:58       ` Aneesh Kumar K.V
2019-06-14 14:59         ` Qian Cai [this message]
2019-06-14 18:03           ` Dan Williams
2019-06-14 18:57             ` Dan Williams
2019-06-14 19:40               ` Qian Cai
2019-06-14 19:48                 ` Dan Williams
2019-06-14 20:43                   ` Qian Cai
2019-06-16 15:42                     ` Dan Williams
2019-06-17  2:25                       ` Qian Cai
2019-06-14 15:35         ` Oscar Salvador
2019-06-14 16:18           ` Aneesh Kumar K.V
2019-06-14 16:22             ` Dan Williams
2019-06-14 16:26               ` Aneesh Kumar K.V
2019-06-14 16:36                 ` Dan Williams
2019-06-14 16:50                   ` Aneesh Kumar K.V
2019-06-14 16:55                   ` Aneesh Kumar K.V
2019-06-14 17:08                     ` Jeff Moyer
2019-06-14 17:14                       ` Dan Williams
2019-06-14 17:40                       ` Aneesh Kumar K.V
2019-06-16  3:49               ` Aneesh Kumar K.V
2019-06-17 17:21                 ` Dan Williams
2019-06-13 18:42   ` Qian Cai
2019-06-14  1:17     ` Dan Williams
2019-06-14  1:29       ` Qian Cai

Reply instructions:

You may reply publically 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=1560524365.5154.21.camel@lca.pw \
    --to=cai@lca.pw \
    --cc=akpm@linux-foundation.org \
    --cc=aneesh.kumar@linux.ibm.com \
    --cc=dan.j.williams@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=osalvador@suse.de \
    /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

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org linux-mm@archiver.kernel.org
	public-inbox-index linux-mm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox