From: Oscar Salvador <osalvador@suse.de>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Qian Cai <cai@lca.pw>, Dan Williams <dan.j.williams@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
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 17:35:39 +0200 [thread overview]
Message-ID: <20190614153535.GA9900@linux> (raw)
In-Reply-To: <87lfy4ilvj.fsf@linux.ibm.com>
On Fri, Jun 14, 2019 at 02:28:40PM +0530, Aneesh Kumar K.V wrote:
> 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.
>
> 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;
I might be missing something, but is this right?
Having a section_nr above NR_MEM_SECTIONS is invalid, but if we return 0 here,
vmemmap_populate will go on and populate it.
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2019-06-14 15:35 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 19:15 [PATCH -next] mm/hotplug: skip bad PFNs from pfn_to_online_page() 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
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 [this message]
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
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