From: Ingo Molnar <mingo@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>, Tejun Heo <tj@kernel.org>,
Zhang Yanfei <zhangyanfei.yes@gmail.com>,
Zhang Yanfei <zhangyanfei@cn.fujitsu.com>,
Toshi Kani <toshi.kani@hp.com>, Ingo Molnar <mingo@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH part2 v2 0/8] Arrange hotpluggable memory as ZONE_MOVABLE
Date: Wed, 16 Oct 2013 09:03:44 +0200 [thread overview]
Message-ID: <20131016070343.GD22509@gmail.com> (raw)
In-Reply-To: <525D7BDE.4070400@zytor.com>
* H. Peter Anvin <hpa@zytor.com> wrote:
> On 10/14/2013 11:50 PM, Ingo Molnar wrote:
> >
> > So if anyone can implement it using huge pages, with a really fast
> > __va() and __pa() implementation, then it might be possible. But
> > that's a pretty major surgery on x86.
>
> Well, we already *have* a way to deal with that for Xen (by inserting an
> otherwise nonexistent logical level.) I'm wondering if those interfaces
> could be (ab)used for this as well, or if that is functionally
> equivalent to saying that this should be done in a hypervisor.
It's not _that_ complex, and it does not need a separate security layer.
I have this distinct memory that I saw working patches that have paged all
of the kernel's data, more than a decade ago. It was all rather
disgusting, because those patches worked on the 4K level - but if a 2MB
granular solution can be found in an elegant fashion then I think we could
reconsider.
It definitely wasn't hypervisor thick. It probably needs a good hash for
virtual address transformations, and all DMA has to be managed [these days
we do that via the IOMMU anyway] but that's pretty much all - kernel
virtual memory is reconfigured extremely rarely, so all that could be sped
up for reads and mirrored per node and kept lockless, etc. etc. [Plus a
metric ton of details.]
Thanks,
Ingo
next prev parent reply other threads:[~2013-10-16 7:03 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-12 6:00 [PATCH part2 v2 0/8] Arrange hotpluggable memory as ZONE_MOVABLE Zhang Yanfei
2013-10-12 6:00 ` Zhang Yanfei
2013-10-12 6:00 ` Zhang Yanfei
2013-10-12 6:03 ` [PATCH part2 v2 1/8] x86: get pg_data_t's memory from other node Zhang Yanfei
2013-10-12 6:03 ` Zhang Yanfei
2013-10-12 6:03 ` Zhang Yanfei
2013-10-12 6:04 ` [PATCH part2 v2 2/8] memblock, numa: Introduce flag into memblock Zhang Yanfei
2013-10-12 6:04 ` Zhang Yanfei
2013-10-12 6:04 ` Zhang Yanfei
2013-10-12 6:05 ` [PATCH part2 v2 3/8] memblock, mem_hotplug: Introduce MEMBLOCK_HOTPLUG flag to mark hotpluggable regions Zhang Yanfei
2013-10-12 6:05 ` Zhang Yanfei
2013-10-12 6:05 ` Zhang Yanfei
2013-10-12 6:06 ` [PATCH part2 v2 4/8] memblock: Make memblock_set_node() support different memblock_type Zhang Yanfei
2013-10-12 6:06 ` Zhang Yanfei
2013-10-12 6:06 ` Zhang Yanfei
2013-10-12 6:07 ` [PATCH part2 v2 5/8] acpi, numa, mem_hotplug: Mark hotpluggable memory in memblock Zhang Yanfei
2013-10-12 6:07 ` Zhang Yanfei
2013-10-12 6:07 ` Zhang Yanfei
2013-10-12 6:08 ` [PATCH part2 v2 6/8] acpi, numa, mem_hotplug: Mark all nodes the kernel resides un-hotpluggable Zhang Yanfei
2013-10-12 6:08 ` Zhang Yanfei
2013-10-12 6:08 ` Zhang Yanfei
2013-10-12 6:09 ` [PATCH part2 v2 7/8] memblock, mem_hotplug: Make memblock skip hotpluggable regions if needed Zhang Yanfei
2013-10-12 6:09 ` Zhang Yanfei
2013-10-12 6:09 ` Zhang Yanfei
2013-10-12 6:09 ` [PATCH part2 v2 8/8] x86, numa, acpi, memory-hotplug: Make movable_node have higher priority Zhang Yanfei
2013-10-12 6:09 ` Zhang Yanfei
2013-10-12 6:09 ` Zhang Yanfei
[not found] ` <525B19C3.9040907@gmail.com>
[not found] ` <20131014133835.GG4722@htj.dyndns.org>
[not found] ` <525BFCF3.5010908@gmail.com>
[not found] ` <20131014142719.GI4722@htj.dyndns.org>
[not found] ` <525C02DC.4050706@gmail.com>
[not found] ` <20131014145131.GJ4722@htj.dyndns.org>
[not found] ` <525C0866.2010808@gmail.com>
[not found] ` <20131014151902.GL4722@htj.dyndns.org>
2013-10-14 15:34 ` [PATCH part2 v2 0/8] Arrange hotpluggable memory as ZONE_MOVABLE Zhang Yanfei
2013-10-14 19:34 ` Yinghai Lu
2013-10-14 20:04 ` Tejun Heo
2013-10-14 20:37 ` Yinghai Lu
2013-10-14 20:42 ` H. Peter Anvin
2013-10-15 6:50 ` Ingo Molnar
2013-10-15 17:31 ` H. Peter Anvin
2013-10-16 7:03 ` Ingo Molnar [this message]
2013-10-14 20:55 ` Tejun Heo
2013-10-15 1:40 ` Zhang Yanfei
2013-10-15 2:25 ` Yinghai Lu
2013-10-15 13:16 ` Tejun Heo
2013-10-14 20:35 ` H. Peter Anvin
2013-10-14 20:42 ` Yinghai Lu
2013-10-14 20:49 ` H. Peter Anvin
2013-11-13 13:50 ` Zhang Yanfei
2013-11-13 13:50 ` Zhang Yanfei
2013-11-19 9:56 ` Zhang Yanfei
2013-11-19 9:56 ` Zhang Yanfei
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