Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-17 Thread Vinod Koul
On Wed, Aug 16, 2017 at 10:16:31AM -0700, Dave Jiang wrote: > > > On 08/16/2017 10:06 AM, Dan Williams wrote: > > On Wed, Aug 16, 2017 at 9:50 AM, Vinod Koul wrote: > >> On Thu, Aug 03, 2017 at 09:14:13AM -0700, Dan Williams wrote: > >>> All my suggestions would involve a

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-16 Thread Dan Williams
On Wed, Aug 16, 2017 at 10:16 AM, Dave Jiang wrote: > > > On 08/16/2017 10:06 AM, Dan Williams wrote: >> On Wed, Aug 16, 2017 at 9:50 AM, Vinod Koul wrote: >>> On Thu, Aug 03, 2017 at 09:14:13AM -0700, Dan Williams wrote: >>> Do we need a

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-16 Thread Dave Jiang
On 08/16/2017 10:06 AM, Dan Williams wrote: > On Wed, Aug 16, 2017 at 9:50 AM, Vinod Koul wrote: >> On Thu, Aug 03, 2017 at 09:14:13AM -0700, Dan Williams wrote: >> Do we need a new API / new function, or new capability? > Hmmm...you are right. I

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-16 Thread Dan Williams
On Wed, Aug 16, 2017 at 9:50 AM, Vinod Koul wrote: > On Thu, Aug 03, 2017 at 09:14:13AM -0700, Dan Williams wrote: >> >> > Do we need a new API / new function, or new capability? >> >> Hmmm...you are right. I wonder if we need something like DMA_SG >> >>

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-16 Thread Vinod Koul
On Thu, Aug 03, 2017 at 09:14:13AM -0700, Dan Williams wrote: > >> > Do we need a new API / new function, or new capability? > >> Hmmm...you are right. I wonder if we need something like DMA_SG > >> cap > >> > >> > >> >>> > >> >>>

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Ross Zwisler
On Wed, Aug 02, 2017 at 11:41:25AM -0700, Dave Jiang wrote: > Adding DMA support for pmem blk reads. This provides signficant CPU > reduction with large memory reads with good performance. DMAs are triggered > with test against bio_multiple_segment(), so the small I/Os (4k or less?) > are still

RE: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Allen Hubbe
From: Dave Jiang > On 08/03/2017 09:14 AM, Dan Williams wrote: > > On Thu, Aug 3, 2017 at 8:55 AM, Vinod Koul wrote: > >> On Thu, Aug 03, 2017 at 08:06:07PM +0530, Jiang, Dave wrote: > On Aug 3, 2017, at 1:56 AM, Koul, Vinod wrote: > > On Thu,

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Dave Jiang
On 08/03/2017 09:14 AM, Dan Williams wrote: > On Thu, Aug 3, 2017 at 8:55 AM, Vinod Koul wrote: >> On Thu, Aug 03, 2017 at 08:06:07PM +0530, Jiang, Dave wrote: >>> >>> On Aug 3, 2017, at 1:56 AM, Koul, Vinod wrote: > On Thu, Aug 03,

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Dan Williams
On Thu, Aug 3, 2017 at 8:55 AM, Vinod Koul wrote: > On Thu, Aug 03, 2017 at 08:06:07PM +0530, Jiang, Dave wrote: >> >> >> > On Aug 3, 2017, at 1:56 AM, Koul, Vinod wrote: >> > >> >> On Thu, Aug 03, 2017 at 11:06:13AM +0530, Jiang, Dave wrote: >> >> >>

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Vinod Koul
On Thu, Aug 03, 2017 at 08:06:07PM +0530, Jiang, Dave wrote: > > > > On Aug 3, 2017, at 1:56 AM, Koul, Vinod wrote: > > > >> On Thu, Aug 03, 2017 at 11:06:13AM +0530, Jiang, Dave wrote: > >> > >> > On Aug 2, 2017, at 10:25 PM, Koul, Vinod

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Jiang, Dave
> On Aug 3, 2017, at 1:56 AM, Koul, Vinod wrote: > >> On Thu, Aug 03, 2017 at 11:06:13AM +0530, Jiang, Dave wrote: >> >> On Aug 2, 2017, at 10:25 PM, Koul, Vinod wrote: On Thu, Aug 03, 2017 at 10:41:51AM +0530, Jiang, Dave wrote:

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-03 Thread Vinod Koul
On Thu, Aug 03, 2017 at 11:06:13AM +0530, Jiang, Dave wrote: > > > > On Aug 2, 2017, at 10:25 PM, Koul, Vinod wrote: > > > >> On Thu, Aug 03, 2017 at 10:41:51AM +0530, Jiang, Dave wrote: > >> > >> > On Aug 2, 2017, at 9:58 PM, Koul, Vinod

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Jiang, Dave
> On Aug 2, 2017, at 10:25 PM, Koul, Vinod wrote: > >> On Thu, Aug 03, 2017 at 10:41:51AM +0530, Jiang, Dave wrote: >> >> On Aug 2, 2017, at 9:58 PM, Koul, Vinod wrote: On Wed, Aug 02, 2017 at 02:13:56PM -0700, Dave Jiang wrote:

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Vinod Koul
On Thu, Aug 03, 2017 at 10:41:51AM +0530, Jiang, Dave wrote: > > > > On Aug 2, 2017, at 9:58 PM, Koul, Vinod wrote: > > > >> On Wed, Aug 02, 2017 at 02:13:56PM -0700, Dave Jiang wrote: > >> > >> > >>> On 08/02/2017 02:10 PM, Sinan Kaya wrote: > >>> On 8/2/2017 4:52 PM,

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Jiang, Dave
> On Aug 2, 2017, at 9:58 PM, Koul, Vinod wrote: > >> On Wed, Aug 02, 2017 at 02:13:56PM -0700, Dave Jiang wrote: >> >> >>> On 08/02/2017 02:10 PM, Sinan Kaya wrote: >>> On 8/2/2017 4:52 PM, Dave Jiang wrote: > Do we need a new API / new function, or new capability?

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Vinod Koul
On Wed, Aug 02, 2017 at 02:13:56PM -0700, Dave Jiang wrote: > > > On 08/02/2017 02:10 PM, Sinan Kaya wrote: > > On 8/2/2017 4:52 PM, Dave Jiang wrote: > >>> Do we need a new API / new function, or new capability? > >> Hmmm...you are right. I wonder if we need something like DMA_SG cap > >> >

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Dave Jiang
On 08/02/2017 02:10 PM, Sinan Kaya wrote: > On 8/2/2017 4:52 PM, Dave Jiang wrote: >>> Do we need a new API / new function, or new capability? >> Hmmm...you are right. I wonder if we need something like DMA_SG cap >> >> > > Unfortunately, DMA_SG means something else. Maybe, we need

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Sinan Kaya
On 8/2/2017 4:52 PM, Dave Jiang wrote: >> Do we need a new API / new function, or new capability? > Hmmm...you are right. I wonder if we need something like DMA_SG cap > > Unfortunately, DMA_SG means something else. Maybe, we need DMA_MEMCPY_SG to be similar with DMA_MEMSET_SG. enum

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Dave Jiang
On 08/02/2017 12:22 PM, Sinan Kaya wrote: > On 8/2/2017 2:41 PM, Dave Jiang wrote: >> if (queue_mode == PMEM_Q_MQ) { >> +chan = dma_find_channel(DMA_MEMCPY); >> +if (!chan) { >> +queue_mode = PMEM_Q_BIO; >> +dev_warn(dev,

Re: [PATCH v2 5/5] libnvdimm: add DMA support for pmem blk-mq

2017-08-02 Thread Sinan Kaya
On 8/2/2017 2:41 PM, Dave Jiang wrote: > if (queue_mode == PMEM_Q_MQ) { > + chan = dma_find_channel(DMA_MEMCPY); > + if (!chan) { > + queue_mode = PMEM_Q_BIO; > + dev_warn(dev, "Forced back to PMEM_Q_BIO, no DMA\n"); > +