From: Christoph Hellwig <hch@lst.de>
To: David Rientjes <rientjes@google.com>
Cc: Christoph Hellwig <hch@lst.de>,
Robin Murphy <robin.murphy@arm.com>,
"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
"Singh, Brijesh" <brijesh.singh@amd.com>,
"Grimm, Jon" <jon.grimm@amd.com>,
baekhw@google.com,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Subject: Re: [rfc] dma-mapping: preallocate unencrypted DMA atomic pool
Date: Thu, 9 Jan 2020 15:31:08 +0100 [thread overview]
Message-ID: <20200109143108.GA22656@lst.de> (raw)
In-Reply-To: <alpine.DEB.2.21.2001071152020.183706@chino.kir.corp.google.com>
On Tue, Jan 07, 2020 at 11:57:24AM -0800, David Rientjes wrote:
> I'll rely on Thomas to chime in if this doesn't make sense for the SEV
> usecase.
>
> I think the sizing of the single atomic pool needs to be determined. Our
> peak usage that we have measured from NVMe is ~1.4MB and atomic_pool is
> currently sized to 256KB by default. I'm unsure at this time if we need
> to be able to dynamically expand this pool with a kworker.
>
> Maybe when CONFIG_AMD_MEM_ENCRYPT is enabled this atomic pool should be
> sized to 2MB or so and then when it reaches half capacity we schedule some
> background work to dynamically increase it? That wouldn't be hard unless
> the pool can be rapidly depleted.
>
Note that a non-coherent architecture with the same workload would need
the same size.
> Do we want to increase the atomic pool size by default and then do
> background dynamic expansion?
For now I'd just scale with system memory size.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: David Rientjes <rientjes@google.com>
Cc: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
"Singh, Brijesh" <brijesh.singh@amd.com>,
"Grimm, Jon" <jon.grimm@amd.com>,
baekhw@google.com,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [rfc] dma-mapping: preallocate unencrypted DMA atomic pool
Date: Thu, 9 Jan 2020 15:31:08 +0100 [thread overview]
Message-ID: <20200109143108.GA22656@lst.de> (raw)
In-Reply-To: <alpine.DEB.2.21.2001071152020.183706@chino.kir.corp.google.com>
On Tue, Jan 07, 2020 at 11:57:24AM -0800, David Rientjes wrote:
> I'll rely on Thomas to chime in if this doesn't make sense for the SEV
> usecase.
>
> I think the sizing of the single atomic pool needs to be determined. Our
> peak usage that we have measured from NVMe is ~1.4MB and atomic_pool is
> currently sized to 256KB by default. I'm unsure at this time if we need
> to be able to dynamically expand this pool with a kworker.
>
> Maybe when CONFIG_AMD_MEM_ENCRYPT is enabled this atomic pool should be
> sized to 2MB or so and then when it reaches half capacity we schedule some
> background work to dynamically increase it? That wouldn't be hard unless
> the pool can be rapidly depleted.
>
Note that a non-coherent architecture with the same workload would need
the same size.
> Do we want to increase the atomic pool size by default and then do
> background dynamic expansion?
For now I'd just scale with system memory size.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-01-09 14:31 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-01 1:54 [rfc] dma-mapping: preallocate unencrypted DMA atomic pool David Rientjes
2020-01-01 1:54 ` David Rientjes via iommu
2020-01-06 17:34 ` Robin Murphy
2020-01-06 17:34 ` Robin Murphy
2020-01-07 10:54 ` Christoph Hellwig
2020-01-07 10:54 ` Christoph Hellwig
2020-01-07 19:57 ` David Rientjes
2020-01-07 19:57 ` David Rientjes via iommu
2020-01-09 14:31 ` Christoph Hellwig [this message]
2020-01-09 14:31 ` Christoph Hellwig
2020-01-09 18:58 ` David Rientjes
2020-01-09 18:58 ` David Rientjes via iommu
2020-01-17 15:28 ` Tom Lendacky
2020-01-17 15:28 ` Tom Lendacky
2020-02-28 9:27 ` David Rientjes
2020-02-28 9:27 ` David Rientjes via iommu
2020-03-02 0:05 ` [rfc 0/6] unencrypted atomic DMA pools with dynamic expansion David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-02 0:05 ` [rfc 1/6] dma-mapping: pass device to atomic allocation functions David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-02 0:05 ` [rfc 2/6] dma-remap: add additional atomic pools to map to gfp mask David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-05 15:42 ` Christoph Hellwig
2020-03-05 15:42 ` Christoph Hellwig
2020-03-02 0:05 ` [rfc 3/6] dma-remap: wire up the atomic pools depending on " David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-05 15:43 ` Christoph Hellwig
2020-03-05 15:43 ` Christoph Hellwig
2020-03-02 0:05 ` [rfc 4/6] dma-remap: dynamically expanding atomic pools David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-03 22:29 ` David Rientjes
2020-03-03 22:29 ` David Rientjes via iommu
2020-03-02 0:05 ` [rfc 5/6] dma-direct: atomic allocations must come from unencrypted pools David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-05 15:44 ` Christoph Hellwig
2020-03-05 15:44 ` Christoph Hellwig
2020-03-07 0:36 ` David Rientjes
2020-03-07 0:36 ` David Rientjes via iommu
2020-03-10 18:47 ` Christoph Hellwig
2020-03-10 18:47 ` Christoph Hellwig
2020-03-02 0:05 ` [rfc 6/6] dma-remap: double the default DMA coherent pool size David Rientjes
2020-03-02 0:05 ` David Rientjes via iommu
2020-03-05 15:45 ` Christoph Hellwig
2020-03-05 15:45 ` Christoph Hellwig
2020-04-08 21:21 ` [rfc v2 0/6] unencrypted atomic DMA pools with dynamic expansion David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-08 21:21 ` [rfc v2 1/6] dma-remap: separate DMA atomic pools from direct remap code David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-14 6:35 ` Christoph Hellwig
2020-04-14 6:35 ` Christoph Hellwig
2020-04-08 21:21 ` [rfc v2 2/6] dma-pool: add additional coherent pools to map to gfp mask David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-08 21:21 ` [rfc v2 3/6] dma-pool: dynamically expanding atomic pools David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-08 21:21 ` [rfc v2 4/6] dma-direct: atomic allocations must come from atomic coherent pools David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-09 21:24 ` Tom Lendacky
2020-04-09 21:24 ` Tom Lendacky
2020-04-14 19:18 ` David Rientjes
2020-04-14 19:18 ` David Rientjes via iommu
2020-04-14 6:43 ` Christoph Hellwig
2020-04-14 6:43 ` Christoph Hellwig
2020-04-14 19:20 ` David Rientjes
2020-04-14 19:20 ` David Rientjes via iommu
2020-04-08 21:21 ` [rfc v2 5/6] x86/mm: unencrypted non-blocking DMA allocations use " David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-08 21:21 ` [rfc v2 6/6] dma-pool: scale the default DMA coherent pool size with memory capacity David Rientjes
2020-04-08 21:21 ` David Rientjes via iommu
2020-04-10 14:55 ` [rfc v2 3/6] dma-pool: dynamically expanding atomic pools Hillf Danton
2020-04-10 19:37 ` David Rientjes
2020-04-10 19:37 ` David Rientjes via iommu
2020-04-14 6:44 ` Christoph Hellwig
2020-04-14 6:44 ` Christoph Hellwig
2020-04-14 19:23 ` David Rientjes
2020-04-14 19:23 ` David Rientjes via iommu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200109143108.GA22656@lst.de \
--to=hch@lst.de \
--cc=Thomas.Lendacky@amd.com \
--cc=baekhw@google.com \
--cc=brijesh.singh@amd.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jon.grimm@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rientjes@google.com \
--cc=robin.murphy@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.