From: Christoph Hellwig <hch@infradead.org>
To: js1304@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Vlastimil Babka <vbabka@suse.cz>,
Laura Abbott <labbott@redhat.com>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
Mel Gorman <mgorman@techsingularity.net>,
Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Roman Gushchin <guro@fb.com>, Minchan Kim <minchan@kernel.org>,
Rik van Riel <riel@surriel.com>,
Christian Koenig <christian.koenig@amd.com>,
Huang Rui <ray.huang@amd.com>,
Eric Biederman <ebiederm@xmission.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Pavel Machek <pavel@ucw.cz>,
kernel-team@lge.com, Christoph Hellwig <hch@infradead.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v2 07/10] mm: separate PageHighMem() and PageHighMemZone() use case
Date: Fri, 1 May 2020 05:30:52 -0700 [thread overview]
Message-ID: <20200501123052.GD21897@infradead.org> (raw)
In-Reply-To: <1588130803-20527-8-git-send-email-iamjoonsoo.kim@lge.com>
On Wed, Apr 29, 2020 at 12:26:40PM +0900, js1304@gmail.com wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
>
> Until now, PageHighMem() is used for two different cases. One is to check
> if there is a direct mapping for this page or not. The other is to check
> the zone of this page, that is, weather it is the highmem type zone or not.
>
> Now, we have separate functions, PageHighMem() and PageHighMemZone() for
> each cases. Use appropriate one.
>
> Note that there are some rules to determine the proper macro.
>
> 1. If PageHighMem() is called for checking if the direct mapping exists
> or not, use PageHighMem().
> 2. If PageHighMem() is used to predict the previous gfp_flags for
> this page, use PageHighMemZone(). The zone of the page is related to
> the gfp_flags.
> 3. If purpose of calling PageHighMem() is to count highmem page and
> to interact with the system by using this count, use PageHighMemZone().
> This counter is usually used to calculate the available memory for an
> kernel allocation and pages on the highmem zone cannot be available
> for an kernel allocation.
> 4. Otherwise, use PageHighMemZone(). It's safe since it's implementation
> is just copy of the previous PageHighMem() implementation and won't
> be changed.
>
> I apply the rule #3 for this patch.
>
> Acked-by: Roman Gushchin <guro@fb.com>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> ---
> mm/memory_hotplug.c | 2 +-
> mm/page_alloc.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 555137b..891c214 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -593,7 +593,7 @@ void generic_online_page(struct page *page, unsigned int order)
> __free_pages_core(page, order);
> totalram_pages_add(1UL << order);
> #ifdef CONFIG_HIGHMEM
> - if (PageHighMem(page))
> + if (PageHighMemZone(page))
> totalhigh_pages_add(1UL << order);
> #endif
> }
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index fc5919e..7fe5115 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7444,7 +7444,7 @@ void adjust_managed_page_count(struct page *page, long count)
> atomic_long_add(count, &page_zone(page)->managed_pages);
> totalram_pages_add(count);
> #ifdef CONFIG_HIGHMEM
> - if (PageHighMem(page))
> + if (PageHighMemZone(page))
> totalhigh_pages_add(count);
> #endif
This function already uses the page_zone structure above, I think
life would be easier of you compare against that, as that makes
the code more obvious.
next prev parent reply other threads:[~2020-05-01 12:30 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 3:26 [PATCH v2 00/10] change the implementation of the PageHighMem() js1304
2020-04-29 3:26 ` [PATCH v2 01/10] mm/page-flags: introduce PageHighMemZone() js1304
2020-04-29 3:26 ` [PATCH v2 02/10] drm/ttm: separate PageHighMem() and PageHighMemZone() use case js1304
2020-04-29 3:26 ` [PATCH v2 03/10] kexec: " js1304
2020-05-01 14:03 ` Eric W. Biederman
2020-05-04 3:10 ` Joonsoo Kim
2020-05-04 14:03 ` Eric W. Biederman
2020-05-04 21:59 ` [RFC][PATCH] kexec: Teach indirect pages how to live in high memory Eric W. Biederman
2020-05-05 17:44 ` Hari Bathini
2020-05-05 18:39 ` Eric W. Biederman
2020-10-09 1:35 ` Joonsoo Kim
2020-05-06 5:23 ` [PATCH v2 03/10] kexec: separate PageHighMem() and PageHighMemZone() use case Joonsoo Kim
2020-04-29 3:26 ` [PATCH v2 04/10] power: " js1304
2020-05-01 12:22 ` Christoph Hellwig
2020-05-04 3:01 ` Joonsoo Kim
2020-04-29 3:26 ` [PATCH v2 05/10] mm/gup: " js1304
2020-05-01 12:24 ` Christoph Hellwig
2020-05-04 3:02 ` Joonsoo Kim
2020-04-29 3:26 ` [PATCH v2 06/10] mm/hugetlb: " js1304
2020-05-01 12:26 ` Christoph Hellwig
2020-05-04 3:03 ` Joonsoo Kim
2020-04-29 3:26 ` [PATCH v2 07/10] mm: " js1304
2020-05-01 12:30 ` Christoph Hellwig [this message]
2020-05-04 3:08 ` Joonsoo Kim
2020-04-29 3:26 ` [PATCH v2 08/10] mm/page_alloc: correct the use of is_highmem_idx() js1304
2020-04-29 3:26 ` [PATCH v2 09/10] mm/migrate: replace PageHighMem() with open-code js1304
2020-04-29 3:26 ` [PATCH v2 10/10] mm/page-flags: change the implementation of the PageHighMem() js1304
2020-04-30 1:47 ` [PATCH v2 00/10] " Andrew Morton
2020-05-01 10:52 ` Joonsoo Kim
2020-05-01 10:55 ` Christoph Hellwig
2020-05-01 12:15 ` Joonsoo Kim
2020-05-01 12:34 ` Christoph Hellwig
2020-05-04 3:09 ` Joonsoo Kim
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