On 5/20/22 17:23, John Garry wrote:
> Streaming DMA mappings may be considerably slower when mappings go through
> an IOMMU and the total mapping length is somewhat long. This is because the
> IOMMU IOVA code allocates and free an IOVA for each mapping, which may
> affect performance.
>
> For perf
On 5/20/22 17:23, John Garry wrote:
> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which
> allows the drivers to know the optimal mapping limit and thus limit the
> requested IOVA lengths.
>
> This value is based on the IOVA rcache range limit, as IOVAs allocated
> above this
On 5/20/22 17:23, John Garry wrote:
> ATA devices (struct ata_device) have a max_sectors field which is
> configured internally in libata. This is then used to (re)configure the
> associated sdev request queue max_sectors value from how it is earlier set
> in __scsi_init_queue(). In __scsi_init_que
On 5/20/22 17:23, John Garry wrote:
> Streaming DMA mapping involving an IOMMU may be much slower for larger
> total mapping size. This is because every IOMMU DMA mapping requires an
> IOVA to be allocated and freed. IOVA sizes above a certain limit are not
> cached, which can have a big impact on
On 2022/05/22 22:13, Christoph Hellwig wrote:
> The whole series looks fine to me. I'll happily queue it up in the
> dma-mapping tree if the SCSI and ATA maintainers are ok with that.
>
Fine with me. I sent an acked-by for the libata bit.
--
Damien Le Moal
Western Digital Research
On 2022/05/23 16:01, John Garry wrote:
> On 21/05/2022 00:33, Damien Le Moal wrote:
>
> Hi Damien,
>
>>> +unsigned long iova_rcache_range(void)
>> Why not a size_t return type ?
>
> The IOVA code generally uses unsigned long for size/range while
> dam-iommu uses size_t as appropiate, so I'm jus
On 2022/05/23 15:53, John Garry wrote:
> On 21/05/2022 00:30, Damien Le Moal wrote:
>>> diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
>>> index f69b77cbf538..a3ae6345473b 100644
>>> --- a/drivers/scsi/hosts.c
>>> +++ b/drivers/scsi/hosts.c
>>> @@ -225,6 +225,11 @@ int scsi_add_host_with_
On 2022/05/20 17:23, John Garry wrote:
> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which
> allows the drivers to know the optimal mapping limit and thus limit the
> requested IOVA lengths.
>
> This value is based on the IOVA rcache range limit, as IOVAs allocated
> above t
On 2022/05/26 19:28, John Garry wrote:
> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which
> allows the drivers to know the optimal mapping limit and thus limit the
> requested IOVA lengths.
>
> This value is based on the IOVA rcache range limit, as IOVAs allocated
> above t
On 6/28/22 00:25, John Garry wrote:
> ATA devices (struct ata_device) have a max_sectors field which is
> configured internally in libata. This is then used to (re)configure the
> associated sdev request queue max_sectors value from how it is earlier set
> in __scsi_init_queue(). In __scsi_init_que
On 6/28/22 16:54, John Garry wrote:
> On 28/06/2022 00:24, Damien Le Moal wrote:
>> On 6/28/22 00:25, John Garry wrote:
>>> ATA devices (struct ata_device) have a max_sectors field which is
>>> configured internally in libata. This is then used to (re)configure the
>>> associated sdev request queue
On 6/29/22 14:40, Christoph Hellwig wrote:
> On Tue, Jun 28, 2022 at 12:33:58PM +0100, John Garry wrote:
>> Well Christoph originally offered to take this series via the dma-mapping
>> tree.
>>
>> @Christoph, is that still ok with you? If so, would you rather I send this
>> libata patch separatel
On 6/29/22 16:43, John Garry wrote:
> On 29/06/2022 06:58, Damien Le Moal wrote:
>> On 6/29/22 14:40, Christoph Hellwig wrote:
>>> On Tue, Jun 28, 2022 at 12:33:58PM +0100, John Garry wrote:
Well Christoph originally offered to take this series via the dma-mapping
tree.
@Christo
On 6/30/22 21:08, John Garry wrote:
> The shost->max_sectors is repeatedly capped according to the host DMA
> mapping limit for each sdev in __scsi_init_queue(). This is unnecessary, so
> set only once when adding the host.
>
> Signed-off-by: John Garry
> ---
> drivers/scsi/hosts.c| 5 +
On 6/30/22 21:08, John Garry wrote:
> Streaming DMA mappings may be considerably slower when mappings go through
> an IOMMU and the total mapping length is somewhat long. This is because the
> IOMMU IOVA code allocates and free an IOVA for each mapping, which may
> affect performance.
>
> For perf
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