From: John Garry <john.garry@huawei.com>
To: Robin Murphy <robin.murphy@arm.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"will@kernel.org" <will@kernel.org>,
"jejb@linux.ibm.com" <jejb@linux.ibm.com>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"hch@lst.de" <hch@lst.de>,
"m.szyprowski@samsung.com" <m.szyprowski@samsung.com>
Cc: "iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
Linuxarm <linuxarm@huawei.com>
Subject: Re: [PATCH 1/6] iommu: Move IOVA power-of-2 roundup into allocator
Date: Mon, 22 Mar 2021 15:01:00 +0000 [thread overview]
Message-ID: <08c0f4b9-8713-fa97-3986-3cfb0d6b820b@huawei.com> (raw)
In-Reply-To: <afc2fc05-a799-cb14-debd-d36afed8f456@arm.com>
On 19/03/2021 19:20, Robin Murphy wrote:
Hi Robin,
>> So then we have the issue of how to dynamically increase this rcache
>> threshold. The problem is that we may have many devices associated with
>> the same domain. So, in theory, we can't assume that when we increase
>> the threshold that some other device will try to fast free an IOVA which
>> was allocated prior to the increase and was not rounded up.
>>
>> I'm very open to better (or less bad) suggestions on how to do this ...
> ...but yes, regardless of exactly where it happens, rounding up or not
> is the problem for rcaches in general. I've said several times that my
> preferred approach is to not change it that dynamically at all, but
> instead treat it more like we treat the default domain type.
>
Can you remind me of that idea? I don't remember you mentioning using
default domain handling as a reference in any context.
Thanks,
John
next prev parent reply other threads:[~2021-03-22 15:04 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 13:25 [PATCH 0/6] dma mapping/iommu: Allow IOMMU IOVA rcache range to be configured John Garry
2021-03-19 13:25 ` [PATCH 1/6] iommu: Move IOVA power-of-2 roundup into allocator John Garry
2021-03-19 16:13 ` Robin Murphy
2021-03-19 16:58 ` John Garry
2021-03-19 19:20 ` Robin Murphy
2021-03-22 15:01 ` John Garry [this message]
2021-03-31 9:58 ` Robin Murphy
2021-04-06 16:54 ` John Garry
2021-04-14 17:44 ` John Garry
2021-03-19 13:25 ` [PATCH 2/6] iova: Add a per-domain count of reserved nodes John Garry
2021-03-19 13:25 ` [PATCH 3/6] iova: Allow rcache range upper limit to be configurable John Garry
2021-03-19 16:25 ` Robin Murphy
2021-03-19 17:26 ` John Garry
2021-03-31 10:53 ` Robin Murphy
2021-03-19 13:25 ` [PATCH 4/6] iommu: Add iommu_dma_set_opt_size() John Garry
2021-03-19 13:25 ` [PATCH 5/6] dma-mapping/iommu: Add dma_set_max_opt_size() John Garry
2021-03-19 17:00 ` Robin Murphy
2021-03-19 18:02 ` John Garry
2021-03-31 8:01 ` Salil Mehta
2021-03-31 8:08 ` Salil Mehta
2021-03-19 13:25 ` [PATCH 6/6] scsi: hisi_sas: Set max optimal DMA size for v3 hw John Garry
2021-03-19 13:40 ` [PATCH 0/6] dma mapping/iommu: Allow IOMMU IOVA rcache range to be configured Christoph Hellwig
2021-03-19 15:42 ` John Garry
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