From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Stefano Stabellini <sstabellini@kernel.org>
Cc: jgross@suse.com, xen-devel@lists.xenproject.org,
Julien.Grall@arm.com, konrad.wilk@oracle.com
Subject: Re: [Xen-devel] [PATCH v2] xen/swiotlb: don't initialize swiotlb twice on arm64
Date: Mon, 3 Jun 2019 19:16:22 -0400 [thread overview]
Message-ID: <25ba38d9-3b9a-a748-714a-25ed207ce090@oracle.com> (raw)
Message-ID: <20190603231622.LKnmovSd-T585oAg62gU9i5SR8f46x4CcO2DQIisqWI@z> (raw)
In-Reply-To: <alpine.DEB.2.21.1906031124300.14041@sstabellini-ThinkPad-T480s>
On 6/3/19 2:25 PM, Stefano Stabellini wrote:
> On Tue, 28 May 2019, Boris Ostrovsky wrote:
>> On 5/28/19 6:48 PM, Stefano Stabellini wrote:
>>> From: Stefano Stabellini <stefanos@xilinx.com>
>>>
>>> On arm64 swiotlb is often (not always) already initialized by mem_init.
>>> We don't want to initialize it twice, which would trigger a second
>>> memory allocation. Moreover, the second memory pool is typically made of
>>> high pages and ends up replacing the original memory pool of low pages.
>>> As a side effect of this change, it is possible to have low pages in
>>> swiotlb-xen on arm64.
>>>
>>> Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
>> Has this been tested on x86?
> Yes, I managed to test it using QEMU. There are no effects on x86, as
> the check io_tlb_start != 0 returns false.
I wonder though whether this is always the case. When we are called
from pci_xen_swiotlb_init_late() for example.
-boris
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next prev parent reply other threads:[~2019-06-03 23:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-28 22:48 [PATCH v2] xen/swiotlb: don't initialize swiotlb twice on arm64 Stefano Stabellini
2019-05-28 22:48 ` [Xen-devel] " Stefano Stabellini
2019-05-28 23:50 ` Boris Ostrovsky
2019-05-28 23:50 ` [Xen-devel] " Boris Ostrovsky
2019-06-03 18:25 ` Stefano Stabellini
2019-06-03 18:25 ` [Xen-devel] " Stefano Stabellini
2019-06-03 23:16 ` Boris Ostrovsky [this message]
2019-06-03 23:16 ` Boris Ostrovsky
2019-06-04 16:51 ` Stefano Stabellini
2019-06-04 19:41 ` Boris Ostrovsky
2019-06-05 14:13 ` Konrad Rzeszutek Wilk
2019-06-05 14:24 ` Juergen Gross
2019-06-13 14:23 ` Konrad Rzeszutek Wilk
2019-06-13 15:04 ` Juergen Gross
2019-06-13 21:00 ` Konrad Rzeszutek Wilk
2019-06-17 8:21 ` Christoph Hellwig
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