Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-22 Thread Dan Williams
On Thu, Aug 20, 2015 at 2:15 PM, Ross Zwisler wrote: > On Thu, 2015-08-20 at 13:27 -0700, Dan Williams wrote: > [...] >> With regards to the fencing, since we already take care to flush >> writes we don't need to fence at all for the flush, right? All we >> care about is that reads see valid data

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Ross Zwisler
On Thu, 2015-08-20 at 13:27 -0700, Dan Williams wrote: [...] > With regards to the fencing, since we already take care to flush > writes we don't need to fence at all for the flush, right? All we > care about is that reads see valid data. We were careful to flush writes, but we could still have (

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Dan Williams
On Thu, Aug 20, 2015 at 12:00 PM, Ross Zwisler wrote: > On Thu, 2015-08-20 at 11:26 -0700, Dan Williams wrote: >> On Thu, Aug 20, 2015 at 11:17 AM, Ross Zwisler >> wrote: >> > On Thu, 2015-08-20 at 10:59 -0700, Dan Williams wrote: >> [..] >> > Ah, I think we're getting confused about the deinterl

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Ross Zwisler
On Thu, 2015-08-20 at 11:26 -0700, Dan Williams wrote: > On Thu, Aug 20, 2015 at 11:17 AM, Ross Zwisler > wrote: > > On Thu, 2015-08-20 at 10:59 -0700, Dan Williams wrote: > [..] > > Ah, I think we're getting confused about the deinterleave part. > > > > The aperture is a set of contiguous address

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Dan Williams
On Thu, Aug 20, 2015 at 11:17 AM, Ross Zwisler wrote: > On Thu, 2015-08-20 at 10:59 -0700, Dan Williams wrote: [..] > Ah, I think we're getting confused about the deinterleave part. > > The aperture is a set of contiguous addresses from the perspective of the > DIMM, but when it's interleaved by t

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Ross Zwisler
On Thu, 2015-08-20 at 10:59 -0700, Dan Williams wrote: > On Thu, Aug 20, 2015 at 9:44 AM, Ross Zwisler > wrote: > > On Wed, 2015-08-19 at 16:06 -0700, Dan Williams wrote: > >> On Wed, Aug 19, 2015 at 3:48 PM, Ross Zwisler > >> wrote: > >> > Add support for the "read flush" _DSM flag, as outlined

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Dan Williams
On Thu, Aug 20, 2015 at 9:44 AM, Ross Zwisler wrote: > On Wed, 2015-08-19 at 16:06 -0700, Dan Williams wrote: >> On Wed, Aug 19, 2015 at 3:48 PM, Ross Zwisler >> wrote: >> > Add support for the "read flush" _DSM flag, as outlined in the DSM spec: >> > >> > http://pmem.io/documents/NVDIMM_DSM_Inte

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Ross Zwisler
On Wed, 2015-08-19 at 16:06 -0700, Dan Williams wrote: > On Wed, Aug 19, 2015 at 3:48 PM, Ross Zwisler > wrote: > > Add support for the "read flush" _DSM flag, as outlined in the DSM spec: > > > > http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf > > > > This flag tells the ND BLK driver t

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Ross Zwisler
On Thu, 2015-08-20 at 11:21 +0100, Will Deacon wrote: > On Wed, Aug 19, 2015 at 11:48:04PM +0100, Ross Zwisler wrote: > > Add support for the "read flush" _DSM flag, as outlined in the DSM spec: > > > > http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf > > > > This flag tells the ND BLK d

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-20 Thread Will Deacon
On Wed, Aug 19, 2015 at 11:48:04PM +0100, Ross Zwisler wrote: > Add support for the "read flush" _DSM flag, as outlined in the DSM spec: > > http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf > > This flag tells the ND BLK driver that it needs to flush the cache lines > associated with the

Re: [PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-19 Thread Dan Williams
On Wed, Aug 19, 2015 at 3:48 PM, Ross Zwisler wrote: > Add support for the "read flush" _DSM flag, as outlined in the DSM spec: > > http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf > > This flag tells the ND BLK driver that it needs to flush the cache lines > associated with the aperture

[PATCH v2] nd_blk: add support for "read flush" DSM flag

2015-08-19 Thread Ross Zwisler
Add support for the "read flush" _DSM flag, as outlined in the DSM spec: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf This flag tells the ND BLK driver that it needs to flush the cache lines associated with the aperture after the aperture is moved but before any new data is read. Th