Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
From:   Qian Cai <cai@lca.pw>
Mime-Version: 1.0 (1.0)
Subject: Re: [PATCH] mm/page_alloc: Add a reason for reserved pages in has_unmovable_pages()
Date:   Thu, 3 Oct 2019 05:05:50 -0400
Message-Id: <7FA7CBE1-E0A9-40E2-B3CA-0896F6D491E5@lca.pw>
References: <1570090257-25001-1-git-send-email-anshuman.khandual@arm.com>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Oscar Salvador <osalvador@suse.de>,
        Mel Gorman <mgorman@techsingularity.net>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Pavel Tatashin <pavel.tatashin@microsoft.com>,
        linux-kernel@vger.kernel.org
In-Reply-To: <1570090257-25001-1-git-send-email-anshuman.khandual@arm.com>
To:     Anshuman Khandual <Anshuman.Khandual@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Oct 3, 2019, at 4:10 AM, Anshuman Khandual <Anshuman.Khandual@arm.com> w=
rote:
>=20
> Having unmovable pages on a given pageblock should be reported correctly
> when required with REPORT_FAILURE flag. But there can be a scenario where a=

> reserved page in the page block will get reported as a generic "unmovable"=

> reason code. Instead this should be changed to a more appropriate reason
> code like "Reserved page".

Isn=E2=80=99t this redundant as it dumps the flags in dump_page() anyway?

>=20
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Mel Gorman <mgorman@techsingularity.net>
> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> mm/page_alloc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>=20
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 15c2050c629b..fbf93ea119d2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8206,8 +8206,10 @@ bool has_unmovable_pages(struct zone *zone, struct p=
age *page, int count,
>=20
>        page =3D pfn_to_page(check);
>=20
> -        if (PageReserved(page))
> +        if (PageReserved(page)) {
> +            reason =3D "Reserved page";
>            goto unmovable;
> +        }
>=20
>        /*
>         * If the zone is movable and we have ruled out all reserved
> --=20
> 2.20.1
>=20