[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20190814140608.GZ17933@dhcp22.suse.cz>
Date: Wed, 14 Aug 2019 16:06:08 +0200
From: Michal Hocko <mhocko@...nel.org>
To: David Hildenbrand <david@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
Dan Williams <dan.j.williams@...el.com>,
Borislav Petkov <bp@...e.de>,
Andrew Morton <akpm@...ux-foundation.org>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Ingo Molnar <mingo@...nel.org>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Nadav Amit <namit@...are.com>,
Wei Yang <richardw.yang@...ux.intel.com>,
Oscar Salvador <osalvador@...e.de>
Subject: Re: [PATCH v1 1/4] resource: Use PFN_UP / PFN_DOWN in
walk_system_ram_range()
On Fri 09-08-19 14:56:58, David Hildenbrand wrote:
> This makes it clearer that we will never call func() with duplicate PFNs
> in case we have multiple sub-page memory resources. All unaligned parts
> of PFNs are completely discarded.
>
> Cc: Dan Williams <dan.j.williams@...el.com>
> Cc: Borislav Petkov <bp@...e.de>
> Cc: Andrew Morton <akpm@...ux-foundation.org>
> Cc: Bjorn Helgaas <bhelgaas@...gle.com>
> Cc: Ingo Molnar <mingo@...nel.org>
> Cc: Dave Hansen <dave.hansen@...ux.intel.com>
> Cc: Nadav Amit <namit@...are.com>
> Cc: Wei Yang <richardw.yang@...ux.intel.com>
> Cc: Oscar Salvador <osalvador@...e.de>
> Signed-off-by: David Hildenbrand <david@...hat.com>
Acked-by: Michal Hocko <mhocko@...e.com>
> ---
> kernel/resource.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 7ea4306503c5..88ee39fa9103 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -487,8 +487,8 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
> while (start < end &&
> !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
> false, &res)) {
> - pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - end_pfn = (res.end + 1) >> PAGE_SHIFT;
> + pfn = PFN_UP(res.start);
> + end_pfn = PFN_DOWN(res.end + 1);
> if (end_pfn > pfn)
> ret = (*func)(pfn, end_pfn - pfn, arg);
> if (ret)
> --
> 2.21.0
--
Michal Hocko
SUSE Labs
Powered by blists - more mailing lists