From: Michal Hocko <mhocko@kernel.org>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Zi Yan <ziy@nvidia.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
mike.kravetz@oracle.com, osalvador@suse.de,
akpm@linux-foundation.org
Subject: Re: [PATCH] mm/isolation: Remove redundant pfn_valid_within() in __first_valid_page()
Date: Thu, 21 Mar 2019 09:07:02 +0100 [thread overview]
Message-ID: <20190321080702.GG8696@dhcp22.suse.cz> (raw)
In-Reply-To: <cda4f247-4eea-decf-3f4a-3dc09364de27@arm.com>
On Thu 21-03-19 11:03:18, Anshuman Khandual wrote:
>
>
> On 03/21/2019 10:31 AM, Zi Yan wrote:
> > On 20 Mar 2019, at 21:13, Anshuman Khandual wrote:
> >
> >> pfn_valid_within() calls pfn_valid() when CONFIG_HOLES_IN_ZONE making it
> >> redundant for both definitions (w/wo CONFIG_MEMORY_HOTPLUG) of the helper
> >> pfn_to_online_page() which either calls pfn_valid() or pfn_valid_within().
> >> pfn_valid_within() being 1 when !CONFIG_HOLES_IN_ZONE is irrelevant either
> >> way. This does not change functionality.
> >>
> >> Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages")
> >
> > I would not say this patch fixes the commit 2ce13640b3f4 from 2017,
> > because the pfn_valid_within() in pfn_to_online_page() was introduced by
> > a recent commit b13bc35193d9e last month. :)
>
> Right, will update the tag with this commit.
The patch is correct but I wouldn't bother to add Fixes tag at all. The
current code is obviously not incorrect. Do you see any actual
performance issue?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-03-21 8:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 4:13 Anshuman Khandual
2019-03-21 5:01 ` Zi Yan
2019-03-21 5:33 ` Anshuman Khandual
2019-03-21 8:07 ` Michal Hocko [this message]
2019-03-21 8:13 ` Anshuman Khandual
2019-03-21 9:42 ` Oscar Salvador
2019-03-21 10:03 ` Michal Hocko
2019-03-22 9:23 ` Michal Hocko
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