From: Michal Hocko <mhocko@kernel.org>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
akpm@linux-foundation.org, will.deacon@arm.com,
catalin.marinas@arm.com, mgorman@techsingularity.net,
james.morse@arm.com, mark.rutland@arm.com, robin.murphy@arm.com,
cpandya@codeaurora.org, arunks@codeaurora.org,
dan.j.williams@intel.com, osalvador@suse.de, logang@deltatee.com,
pasha.tatashin@oracle.com, david@redhat.com, cai@lca.pw
Subject: Re: [PATCH 5/6] mm/memremap: Rename and consolidate SECTION_SIZE
Date: Wed, 3 Apr 2019 11:26:44 +0200 [thread overview]
Message-ID: <20190403092644.GH15605@dhcp22.suse.cz> (raw)
In-Reply-To: <1554265806-11501-6-git-send-email-anshuman.khandual@arm.com>
On Wed 03-04-19 10:00:05, Anshuman Khandual wrote:
> From: Robin Murphy <robin.murphy@arm.com>
>
> Enabling ZONE_DEVICE (through ARCH_HAS_ZONE_DEVICE) for arm64 reveals that
> memremap's internal helpers for sparsemem sections conflict with arm64's
> definitions for hugepages which inherit the name of "sections" from earlier
> versions of the ARM architecture.
>
> Disambiguate memremap by propagating sparsemem's PA_ prefix, to clarify
> that these values are in terms of addresses rather than PFNs (and
> because it's a heck of a lot easier than changing all the arch code).
> SECTION_MASK is unused, so it can just go. While here consolidate single
> instance of PA_SECTION_SIZE from mm/hmm.c as well.
>
> [anshuman: Consolidated mm/hmm.c instance and updated the commit message]
Agreed. mremap shouldn't have redefined SECTION_SIZE in the first place.
This just adds a confusion.
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> include/linux/mmzone.h | 1 +
> kernel/memremap.c | 10 ++++------
> mm/hmm.c | 2 --
> 3 files changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index fba7741..ed7dd27 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -1081,6 +1081,7 @@ static inline unsigned long early_pfn_to_nid(unsigned long pfn)
> * PFN_SECTION_SHIFT pfn to/from section number
> */
> #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
> +#define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT)
> #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
>
> #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
> diff --git a/kernel/memremap.c b/kernel/memremap.c
> index a856cb5..dda1367 100644
> --- a/kernel/memremap.c
> +++ b/kernel/memremap.c
> @@ -14,8 +14,6 @@
> #include <linux/hmm.h>
>
> static DEFINE_XARRAY(pgmap_array);
> -#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
> -#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
>
> #if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
> vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
> @@ -98,8 +96,8 @@ static void devm_memremap_pages_release(void *data)
> put_page(pfn_to_page(pfn));
>
> /* pages are dead and unused, undo the arch mapping */
> - align_start = res->start & ~(SECTION_SIZE - 1);
> - align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
> + align_start = res->start & ~(PA_SECTION_SIZE - 1);
> + align_size = ALIGN(res->start + resource_size(res), PA_SECTION_SIZE)
> - align_start;
>
> nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
> @@ -154,8 +152,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
> if (!pgmap->ref || !pgmap->kill)
> return ERR_PTR(-EINVAL);
>
> - align_start = res->start & ~(SECTION_SIZE - 1);
> - align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
> + align_start = res->start & ~(PA_SECTION_SIZE - 1);
> + align_size = ALIGN(res->start + resource_size(res), PA_SECTION_SIZE)
> - align_start;
> align_end = align_start + align_size - 1;
>
> diff --git a/mm/hmm.c b/mm/hmm.c
> index fe1cd87..ef9e4e6 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -33,8 +33,6 @@
> #include <linux/mmu_notifier.h>
> #include <linux/memory_hotplug.h>
>
> -#define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT)
> -
> #if IS_ENABLED(CONFIG_HMM_MIRROR)
> static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
>
> --
> 2.7.4
>
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-04-03 9:26 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 4:30 [PATCH 0/6] arm64/mm: Enable memory hot remove and ZONE_DEVICE Anshuman Khandual
2019-04-03 4:30 ` [PATCH 1/6] arm64/mm: Enable sysfs based memory hot add interface Anshuman Khandual
2019-04-03 8:20 ` David Hildenbrand
2019-04-03 13:12 ` Robin Murphy
2019-04-04 5:21 ` Anshuman Khandual
2019-04-04 5:25 ` Anshuman Khandual
2019-04-04 8:49 ` David Hildenbrand
2019-04-03 4:30 ` [PATCH 2/6] arm64/mm: Enable memory hot remove Anshuman Khandual
2019-04-03 12:37 ` Robin Murphy
2019-04-03 13:15 ` Steven Price
2019-04-04 6:51 ` Anshuman Khandual
2019-04-04 5:39 ` Anshuman Khandual
2019-04-04 11:58 ` Oscar Salvador
2019-04-04 13:03 ` Anshuman Khandual
2019-04-04 15:19 ` Oscar Salvador
2019-04-03 17:32 ` Logan Gunthorpe
2019-04-03 17:57 ` Robin Murphy
2019-04-04 8:23 ` Anshuman Khandual
2019-04-04 7:07 ` Anshuman Khandual
2019-04-04 9:16 ` Steven Price
2019-04-03 4:30 ` [PATCH 3/6] arm64/mm: Enable struct page allocation from device memory Anshuman Khandual
2019-04-03 4:30 ` [PATCH 4/6] mm/hotplug: Reorder arch_remove_memory() call in __remove_memory() Anshuman Khandual
2019-04-03 8:45 ` Oscar Salvador
2019-04-03 9:17 ` Michal Hocko
2019-04-04 8:32 ` Anshuman Khandual
2019-04-03 9:30 ` David Hildenbrand
2019-04-03 4:30 ` [PATCH 5/6] mm/memremap: Rename and consolidate SECTION_SIZE Anshuman Khandual
2019-04-03 9:26 ` Michal Hocko [this message]
2019-04-03 9:30 ` David Hildenbrand
2019-04-03 4:30 ` [PATCH 6/6] arm64/mm: Enable ZONE_DEVICE Anshuman Khandual
2019-04-03 13:58 ` Robin Murphy
2019-04-03 16:07 ` Jerome Glisse
2019-04-04 5:03 ` Anshuman Khandual
2019-04-04 4:42 ` Anshuman Khandual
2019-04-04 5:04 ` Dan Williams
2019-04-04 9:46 ` Robin Murphy
2019-04-07 22:11 ` Dan Williams
2019-04-08 4:03 ` Ira Weiny
2019-04-08 6:03 ` Anshuman Khandual
2019-04-03 18:08 ` [PATCH 0/6] arm64/mm: Enable memory hot remove and ZONE_DEVICE Dan Williams
2019-04-04 13:11 ` Anshuman Khandual
2019-04-04 9:46 ` [RFC 1/2] mm/vmemmap: Enable vmem_altmap based base page mapping for vmemmap Anshuman Khandual
2019-04-04 9:46 ` [RFC 2/2] arm64/mm: Enable ZONE_DEVICE for all page configs Anshuman Khandual
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=20190403092644.GH15605@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=anshuman.khandual@arm.com \
--cc=arunks@codeaurora.org \
--cc=cai@lca.pw \
--cc=catalin.marinas@arm.com \
--cc=cpandya@codeaurora.org \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=james.morse@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=logang@deltatee.com \
--cc=mark.rutland@arm.com \
--cc=mgorman@techsingularity.net \
--cc=osalvador@suse.de \
--cc=pasha.tatashin@oracle.com \
--cc=robin.murphy@arm.com \
--cc=will.deacon@arm.com \
/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).