Re: [RFC] mmap(MAP_CONTIG)

2017-10-24 Thread Mike Kravetz
On 10/23/2017 03:10 PM, Dave Hansen wrote: > On 10/03/2017 04:56 PM, Mike Kravetz wrote: >> mmap(MAP_CONTIG) would have the following semantics: >> - The entire mapping (length size) would be backed by physically contiguous >> pages. >> - If 'length' physically contiguous pages can not be allocat

Re: [RFC] mmap(MAP_CONTIG)

2017-10-23 Thread Dave Hansen
On 10/03/2017 04:56 PM, Mike Kravetz wrote: > mmap(MAP_CONTIG) would have the following semantics: > - The entire mapping (length size) would be backed by physically contiguous > pages. > - If 'length' physically contiguous pages can not be allocated, then mmap > will fail. > - MAP_CONTIG only

Re: [RFC] mmap(MAP_CONTIG)

2017-10-05 Thread Christopher Lameter
On Thu, 5 Oct 2017, Vlastimil Babka wrote: > On 10/04/2017 01:56 AM, Mike Kravetz wrote: > > At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation > > titled 'User space contiguous memory allocation for DMA' [1]. The slides > Hm I didn't find slides on that link, are they a

Re: [RFC] mmap(MAP_CONTIG)

2017-10-05 Thread Vlastimil Babka
On 10/04/2017 01:56 AM, Mike Kravetz wrote: Hi, > At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation > titled 'User space contiguous memory allocation for DMA' [1]. The slides Hm I didn't find slides on that link, are they available? > point out the performance benefi

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Laura Abbott
On 10/04/2017 10:08 AM, Mike Kravetz wrote: > On 10/04/2017 04:54 AM, Michal Nazarewicz wrote: >> On Tue, Oct 03 2017, Mike Kravetz wrote: >>> At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation >>> titled 'User space contiguous memory allocation for DMA' [1]. The slides >

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Mike Kravetz
On 10/04/2017 09:05 AM, Christopher Lameter wrote: > On Wed, 4 Oct 2017, Anshuman Khandual wrote: > >>> - Using 'pre-allocated' pages in the fault paths may be intrusive. >> >> But we have already faulted in all of them for the mapping and they >> are also locked. Hence there should not be any pag

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Mike Kravetz
On 10/04/2017 06:49 AM, Anshuman Khandual wrote: > On 10/04/2017 05:26 AM, Mike Kravetz wrote: >> At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation >> titled 'User space contiguous memory allocation for DMA' [1]. The slides >> point out the performance benefits of device

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Mike Kravetz
On 10/04/2017 04:54 AM, Michal Nazarewicz wrote: > On Tue, Oct 03 2017, Mike Kravetz wrote: >> At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation >> titled 'User space contiguous memory allocation for DMA' [1]. The slides >> point out the performance benefits of devices t

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Christopher Lameter
On Wed, 4 Oct 2017, Anshuman Khandual wrote: > > - Using 'pre-allocated' pages in the fault paths may be intrusive. > > But we have already faulted in all of them for the mapping and they > are also locked. Hence there should not be any page faults any more > for the VMA. Am I missing something he

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Anshuman Khandual
On 10/04/2017 05:26 AM, Mike Kravetz wrote: > At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation > titled 'User space contiguous memory allocation for DMA' [1]. The slides > point out the performance benefits of devices that can take advantage of > larger physically conti

Re: [RFC] mmap(MAP_CONTIG)

2017-10-04 Thread Michal Nazarewicz
On Tue, Oct 03 2017, Mike Kravetz wrote: > At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation > titled 'User space contiguous memory allocation for DMA' [1]. The slides > point out the performance benefits of devices that can take advantage of > larger physically contiguo