Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-04 Thread Peter Xu
On Fri, Jun 04, 2021 at 11:07:42AM +1000, Alistair Popple wrote: > On Friday, 4 June 2021 12:47:40 AM AEST Peter Xu wrote: > > External email: Use caution opening links or attachments > > > > On Thu, Jun 03, 2021 at 09:39:32PM +1000, Alistair Popple wrote: > > > Reclaim won't run on the page due

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-04 Thread Peter Xu
On Thu, Jun 03, 2021 at 09:39:32PM +1000, Alistair Popple wrote: > Reclaim won't run on the page due to the extra references from the special > swap entries. That sounds reasonable, but I didn't find the point that stops it, probably due to my limited knowledge on the reclaim code. Could you

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-03 Thread Alistair Popple
On Friday, 4 June 2021 12:47:40 AM AEST Peter Xu wrote: > External email: Use caution opening links or attachments > > On Thu, Jun 03, 2021 at 09:39:32PM +1000, Alistair Popple wrote: > > Reclaim won't run on the page due to the extra references from the special > > swap entries. > > That sounds

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-03 Thread Alistair Popple
On Thursday, 3 June 2021 12:37:30 AM AEST Peter Xu wrote: > External email: Use caution opening links or attachments > > On Wed, Jun 02, 2021 at 06:50:37PM +1000, Balbir Singh wrote: > > On Wed, May 26, 2021 at 12:17:18AM -0700, John Hubbard wrote: > > > On 5/25/21 4:51 AM, Balbir Singh wrote: >

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-03 Thread John Hubbard
On 6/2/21 1:50 AM, Balbir Singh wrote: ... only impact the address space of programs using the GPU. Should the exclusively marked range live in the unreclaimable list and recycled back to active/in-active to account for the fact that 1. It is not reclaimable and reclaim will only hurt via page

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-02 Thread Peter Xu
On Wed, Jun 02, 2021 at 06:50:37PM +1000, Balbir Singh wrote: > On Wed, May 26, 2021 at 12:17:18AM -0700, John Hubbard wrote: > > On 5/25/21 4:51 AM, Balbir Singh wrote: > > ... > > > > How beneficial is this code to nouveau users? I see that it permits a > > > > part of OpenCL to be implemented,

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-06-02 Thread Balbir Singh
On Wed, May 26, 2021 at 12:17:18AM -0700, John Hubbard wrote: > On 5/25/21 4:51 AM, Balbir Singh wrote: > ... > > > How beneficial is this code to nouveau users? I see that it permits a > > > part of OpenCL to be implemented, but how useful/important is this in > > > the real world? > > > > That

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-28 Thread Peter Xu
On Fri, May 28, 2021 at 11:48:40AM +1000, Alistair Popple wrote: [...] > > > > > + while (page_vma_mapped_walk()) { > > > > > + /* Unexpected PMD-mapped THP? */ > > > > > + VM_BUG_ON_PAGE(!pvmw.pte, page); > > > > > + > > > > > + if

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-27 Thread Alistair Popple
On Thursday, 27 May 2021 11:04:57 PM AEST Peter Xu wrote: > On Thu, May 27, 2021 at 01:35:39PM +1000, Alistair Popple wrote: > > > > + * > > > > + * @MMU_NOTIFY_EXCLUSIVE: to signal a device driver that the device > > > > will > > > > no + * longer have exclusive access to the page. May ignore the

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-27 Thread Peter Xu
On Thu, May 27, 2021 at 01:35:39PM +1000, Alistair Popple wrote: > > > + * > > > + * @MMU_NOTIFY_EXCLUSIVE: to signal a device driver that the device will > > > no + * longer have exclusive access to the page. May ignore the > > > invalidation that's + * part of make_device_exclusive_range() if

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-26 Thread Alistair Popple
On Thursday, 27 May 2021 5:28:32 AM AEST Peter Xu wrote: > On Mon, May 24, 2021 at 11:27:22PM +1000, Alistair Popple wrote: > > Some devices require exclusive write access to shared virtual > > memory (SVM) ranges to perform atomic operations on that memory. This > > requires CPU page tables to be

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-26 Thread Peter Xu
On Mon, May 24, 2021 at 11:27:22PM +1000, Alistair Popple wrote: > Some devices require exclusive write access to shared virtual > memory (SVM) ranges to perform atomic operations on that memory. This > requires CPU page tables to be updated to deny access whilst atomic > operations are occurring.

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-26 Thread Alistair Popple
On Wednesday, 26 May 2021 5:17:18 PM AEST John Hubbard wrote: > On 5/25/21 4:51 AM, Balbir Singh wrote: > ... > > >> How beneficial is this code to nouveau users? I see that it permits a > >> part of OpenCL to be implemented, but how useful/important is this in > >> the real world? > > > > That

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-26 Thread John Hubbard
On 5/25/21 4:51 AM, Balbir Singh wrote: ... How beneficial is this code to nouveau users? I see that it permits a part of OpenCL to be implemented, but how useful/important is this in the real world? That is a very good question! I've not reviewed the code, but a sample program with the

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-25 Thread Balbir Singh
On Mon, May 24, 2021 at 03:11:57PM -0700, Andrew Morton wrote: > On Mon, 24 May 2021 23:27:22 +1000 Alistair Popple wrote: > > > Some devices require exclusive write access to shared virtual > > memory (SVM) ranges to perform atomic operations on that memory. This > > requires CPU page tables to

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-25 Thread Alistair Popple
On Tuesday, 25 May 2021 11:31:17 AM AEST John Hubbard wrote: > On 5/24/21 3:11 PM, Andrew Morton wrote: > >> ... > >> > >> Documentation/vm/hmm.rst | 17 > >> include/linux/mmu_notifier.h | 6 ++ > >> include/linux/rmap.h | 4 + > >> include/linux/swap.h | 7

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-24 Thread John Hubbard
On 5/24/21 3:11 PM, Andrew Morton wrote: ... Documentation/vm/hmm.rst | 17 include/linux/mmu_notifier.h | 6 ++ include/linux/rmap.h | 4 + include/linux/swap.h | 7 +- include/linux/swapops.h | 44 - mm/hmm.c | 5 +

Re: [Nouveau] [PATCH v9 07/10] mm: Device exclusive memory access

2021-05-24 Thread Andrew Morton
On Mon, 24 May 2021 23:27:22 +1000 Alistair Popple wrote: > Some devices require exclusive write access to shared virtual > memory (SVM) ranges to perform atomic operations on that memory. This > requires CPU page tables to be updated to deny access whilst atomic > operations are occurring. > >