From: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Subject: [RFC] arm64: mm: update max_pfn after memory hotplug
Date: Thu, 23 Sep 2021 15:54:47 -0700 [thread overview]
Message-ID: <cover.1632437225.git.quic_cgoldswo@quicinc.com> (raw)
On arm64 we set max_pfn at boot in arch/arm64/mm/init.c. If you
hotplug in memory after booting up, max_pfn is not updated. This
breaks diagnostic functions executed from user space like
read_page_owner():
https://elixir.bootlin.com/linux/v5.14.7/source/mm/page_owner.c#L472
or kpageflags_read() (see how get_max_dump_pfn() is used):
https://elixir.bootlin.com/linux/v5.14.7/source/fs/proc/page.c#L47
Thus, this patch updates max_pfn and max_low_pfn in arm64's
arch_add_memory() function, mirroring what is updatated during boot:
https://elixir.bootlin.com/linux/v5.14.7/source/arch/arm64/mm/init.c#L448
We would appreciate feedback on any other variables that should be
updated when hotplugging in memory - note that we're mirroring x86, in
that max_pfn is only ever incremented when calling arch_add_memory():
https://elixir.bootlin.com/linux/v5.14.7/source/arch/x86/mm/init_64.c#L958
Sudarshan Rajagopalan (1):
arm64: mm: update max_pfn after memory hotplug
arch/arm64/mm/mmu.c | 5 +++++
1 file changed, 5 insertions(+)
--
2.7.4
next reply other threads:[~2021-09-23 22:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 22:54 Chris Goldsworthy [this message]
2021-09-23 22:54 ` Chris Goldsworthy
2021-09-24 2:47 ` Florian Fainelli
2021-09-24 8:17 ` David Hildenbrand
2021-09-24 20:52 ` Chris Goldsworthy
2021-09-27 15:51 ` David Hildenbrand
2021-09-27 23:22 ` Georgi Djakov
2021-09-28 6:12 ` Chris Goldsworthy
2021-09-28 7:33 ` David Hildenbrand
2021-09-27 17:22 ` Georgi Djakov
2021-09-27 17:34 ` David Hildenbrand
2021-09-27 20:00 ` Georgi Djakov
2021-09-27 20:14 ` David Hildenbrand
2021-09-29 10:10 ` Will Deacon
2021-09-29 10:29 ` David Hildenbrand
2021-09-29 10:42 ` Will Deacon
2021-09-29 10:49 ` David Hildenbrand
2021-09-29 11:03 ` Will Deacon
2021-09-29 12:09 ` David Hildenbrand
2021-09-29 12:51 ` Will Deacon
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