From: Michal Hocko <mhocko@kernel.org>
To: osalvador <osalvador@suse.de>
Cc: Balbir Singh <bsingharora@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Baoquan He <bhe@redhat.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm, memory_hotplug: check zone_movable in has_unmovable_pages
Date: Wed, 7 Nov 2018 09:14:26 +0100 [thread overview]
Message-ID: <20181107081426.GW27423@dhcp22.suse.cz> (raw)
In-Reply-To: <1541577326.3089.2.camel@suse.de>
On Wed 07-11-18 08:55:26, osalvador wrote:
> On Wed, 2018-11-07 at 08:35 +0100, Michal Hocko wrote:
> > On Wed 07-11-18 07:35:18, Balbir Singh wrote:
> > > The check seems to be quite aggressive and in a loop that iterates
> > > pages, but has nothing to do with the page, did you mean to make
> > > the check
> > >
> > > zone_idx(page_zone(page)) == ZONE_MOVABLE
> >
> > Does it make any difference? Can we actually encounter a page from a
> > different zone here?
>
> AFAIK, test_pages_in_a_zone() called from offline_pages() should ensure
> that the range belongs to a unique zone, so we should not encounter
> pages from other zones there, right?
Yes that is the case for memory hotplug. We do assume a single zone at
set_migratetype_isolate where we take the zone->lock. If the
contig_alloc can span multiple zones then it should check for similar.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-11-07 8:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-06 9:55 [PATCH] mm, memory_hotplug: check zone_movable in has_unmovable_pages Michal Hocko
2018-11-06 11:00 ` osalvador
2018-11-06 20:35 ` Balbir Singh
2018-11-07 7:35 ` Michal Hocko
2018-11-07 7:40 ` Michal Hocko
2018-11-07 7:55 ` osalvador
2018-11-07 8:14 ` Michal Hocko [this message]
2018-11-07 12:53 ` Balbir Singh
2018-11-07 13:06 ` Michal Hocko
2018-11-09 10:45 ` Balbir Singh
2018-11-15 3:13 ` Baoquan He
2018-11-15 3:18 ` Baoquan He
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