All the mail mirrored from lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Zeng, Oak" <oak.zeng@intel.com>
Cc: "dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"intel-xe@lists.freedesktop.org" <intel-xe@lists.freedesktop.org>,
	"Brost, Matthew" <matthew.brost@intel.com>,
	"Thomas.Hellstrom@linux.intel.com"
	<Thomas.Hellstrom@linux.intel.com>,
	"Welty, Brian" <brian.welty@intel.com>,
	"Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>,
	"Bommu, Krishnaiah" <krishnaiah.bommu@intel.com>,
	"Vishwanathapura,
	Niranjana" <niranjana.vishwanathapura@intel.com>,
	Leon Romanovsky <leon@kernel.org>
Subject: Re: [PATCH 06/23] drm/xe/svm: Introduce a helper to build sg table from hmm range
Date: Tue, 9 Apr 2024 14:24:18 -0300	[thread overview]
Message-ID: <20240409172418.GA5383@nvidia.com> (raw)
In-Reply-To: <SA1PR11MB6991A4BD0EDDDF051A9A2C5C92072@SA1PR11MB6991.namprd11.prod.outlook.com>

On Tue, Apr 09, 2024 at 04:45:22PM +0000, Zeng, Oak wrote:

> > I saw, I am saying this should not be done. You cannot unmap bits of
> > a sgl mapping if an invalidation comes in.
> 
> You are right, if we register a huge mmu interval notifier to cover
> the whole address space, then we should use dma map/unmap pages to
> map bits of the address space. We will explore this approach.
> 
> Right now, in xe driver, mmu interval notifier is dynamically
> registered with small address range. We map/unmap the whole small
> address ranges each time. So functionally it still works. But it
> might not be as performant as the method you said. 

Please don't do this, it is not how hmm_range_fault() should be
used.

It is intended to be page by page and there is no API surface
available to safely try to construct covering ranges. Drivers
definately should not try to invent such a thing.

> > Please don't use sg list at all for this.
> 
> As explained, we use sg list for device private pages so we can
> re-used the gpu page table update codes. 

I'm asking you not to use SGL lists for that too. SGL lists are not
generic data structures to hold DMA lists.

> > This is not what I'm talking about. The GPU VMA is bound to a specific
> > MM VA, it should not be created on demand.
> 
> Today we have two places where we create gpu vma: 1) create gpu vma
> during a vm_bind ioctl 2) create gpu vma during a page fault of the
> system allocator range (this will be in v2 of this series).

Don't do 2.

> I suspect something dynamic is still necessary, either a vma or a
> page table state (1 vma but many page table state created
> dynamically, as planned in our stage 2). 

I'm expecting you'd populate the page table memory on demand.

> The reason is, we still need some gpu corresponding structure to
> match the cpu vm_area_struct.

Definately not.

> For example, when gpu page fault happens, you look
> up the cpu vm_area_struct for the fault address and create a
> corresponding state/struct. And people can have as many cpu
> vm_area_struct as they want.

No you don't.

You call hmm_range_fault() and it does everything for you. A driver
should never touch CPU VMAs and must not be aware of them in any away.

Jason

  reply	other threads:[~2024-04-09 17:24 UTC|newest]

Thread overview: 198+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-17 22:12 [PATCH 00/23] XeKmd basic SVM support Oak Zeng
2024-01-17 22:12 ` Oak Zeng
2024-01-17 22:12 ` [PATCH 01/23] drm/xe/svm: Add SVM document Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 02/23] drm/xe/svm: Add svm key data structures Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 03/23] drm/xe/svm: create xe svm during vm creation Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 04/23] drm/xe/svm: Trace svm creation Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 05/23] drm/xe/svm: add helper to retrieve svm range from address Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 06/23] drm/xe/svm: Introduce a helper to build sg table from hmm range Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-04-05  0:39   ` Jason Gunthorpe
2024-04-05  3:33     ` Zeng, Oak
2024-04-05 12:37       ` Jason Gunthorpe
2024-04-05 16:42         ` Zeng, Oak
2024-04-05 18:02           ` Jason Gunthorpe
2024-04-09 16:45             ` Zeng, Oak
2024-04-09 17:24               ` Jason Gunthorpe [this message]
2024-04-23 21:17                 ` Zeng, Oak
2024-04-24  2:31                   ` Matthew Brost
2024-04-24 13:57                     ` Jason Gunthorpe
2024-04-24 16:35                       ` Matthew Brost
2024-04-24 16:44                         ` Jason Gunthorpe
2024-04-24 16:56                           ` Matthew Brost
2024-04-24 17:48                             ` Jason Gunthorpe
2024-04-24 13:48                   ` Jason Gunthorpe
2024-04-24 23:59                     ` Zeng, Oak
2024-04-25  1:05                       ` Jason Gunthorpe
2024-04-26  9:55                         ` Thomas Hellström
2024-04-26 12:00                           ` Jason Gunthorpe
2024-04-26 14:49                             ` Thomas Hellström
2024-04-26 16:35                               ` Jason Gunthorpe
2024-04-29  8:25                                 ` Thomas Hellström
2024-04-30 17:30                                   ` Jason Gunthorpe
2024-04-30 18:57                                     ` Daniel Vetter
2024-05-01  0:09                                       ` Jason Gunthorpe
2024-05-02  8:04                                         ` Daniel Vetter
2024-05-02  9:11                                           ` Thomas Hellström
2024-05-02 12:46                                             ` Jason Gunthorpe
2024-05-02 15:01                                               ` Thomas Hellström
2024-05-02 19:25                                                 ` Zeng, Oak
2024-05-03 13:37                                                   ` Jason Gunthorpe
2024-05-03 14:43                                                     ` Zeng, Oak
2024-05-03 16:28                                                       ` Jason Gunthorpe
2024-05-03 20:29                                                         ` Zeng, Oak
2024-05-04  1:03                                                           ` Dave Airlie
2024-05-06 13:04                                                             ` Daniel Vetter
2024-05-06 23:50                                                               ` Matthew Brost
2024-05-07 11:56                                                                 ` Jason Gunthorpe
2024-05-06 13:33                                                           ` Jason Gunthorpe
2024-04-09 17:33               ` Matthew Brost
2024-01-17 22:12 ` [PATCH 07/23] drm/xe/svm: Add helper for binding hmm range to gpu Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 08/23] drm/xe/svm: Add helper to invalidate svm range from GPU Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 09/23] drm/xe/svm: Remap and provide memmap backing for GPU vram Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 10/23] drm/xe/svm: Introduce svm migration function Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 11/23] drm/xe/svm: implement functions to allocate and free device memory Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 12/23] drm/xe/svm: Trace buddy block allocation and free Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 13/23] drm/xe/svm: Handle CPU page fault Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 14/23] drm/xe/svm: trace svm range migration Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 15/23] drm/xe/svm: Implement functions to register and unregister mmu notifier Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 16/23] drm/xe/svm: Implement the mmu notifier range invalidate callback Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 17/23] drm/xe/svm: clean up svm range during process exit Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 18/23] drm/xe/svm: Move a few structures to xe_gt.h Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 19/23] drm/xe/svm: migrate svm range to vram Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 20/23] drm/xe/svm: Populate svm range Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 21/23] drm/xe/svm: GPU page fault support Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-23  2:06   ` Welty, Brian
2024-01-23  2:06     ` Welty, Brian
2024-01-23  3:09     ` Zeng, Oak
2024-01-23  3:09       ` Zeng, Oak
2024-01-23  3:21       ` Making drm_gpuvm work across gpu devices Zeng, Oak
2024-01-23  3:21         ` Zeng, Oak
2024-01-23 11:13         ` Christian König
2024-01-23 11:13           ` Christian König
2024-01-23 19:37           ` Zeng, Oak
2024-01-23 19:37             ` Zeng, Oak
2024-01-23 20:17             ` Felix Kuehling
2024-01-23 20:17               ` Felix Kuehling
2024-01-25  1:39               ` Zeng, Oak
2024-01-25  1:39                 ` Zeng, Oak
2024-01-23 23:56             ` Danilo Krummrich
2024-01-23 23:56               ` Danilo Krummrich
2024-01-24  3:57               ` Zeng, Oak
2024-01-24  3:57                 ` Zeng, Oak
2024-01-24  4:14                 ` Zeng, Oak
2024-01-24  4:14                   ` Zeng, Oak
2024-01-24  6:48                   ` Christian König
2024-01-24  6:48                     ` Christian König
2024-01-25 22:13                 ` Danilo Krummrich
2024-01-25 22:13                   ` Danilo Krummrich
2024-01-24  8:33             ` Christian König
2024-01-24  8:33               ` Christian König
2024-01-25  1:17               ` Zeng, Oak
2024-01-25  1:17                 ` Zeng, Oak
2024-01-25  1:25                 ` David Airlie
2024-01-25  1:25                   ` David Airlie
2024-01-25  5:25                   ` Zeng, Oak
2024-01-25  5:25                     ` Zeng, Oak
2024-01-26 10:09                     ` Christian König
2024-01-26 10:09                       ` Christian König
2024-01-26 20:13                       ` Zeng, Oak
2024-01-26 20:13                         ` Zeng, Oak
2024-01-29 10:10                         ` Christian König
2024-01-29 10:10                           ` Christian König
2024-01-29 20:09                           ` Zeng, Oak
2024-01-29 20:09                             ` Zeng, Oak
2024-01-25 11:00                 ` 回复:Making " 周春明(日月)
2024-01-25 11:00                   ` 周春明(日月)
2024-01-25 17:00                   ` Zeng, Oak
2024-01-25 17:00                     ` Zeng, Oak
2024-01-25 17:15                 ` Making " Felix Kuehling
2024-01-25 17:15                   ` Felix Kuehling
2024-01-25 18:37                   ` Zeng, Oak
2024-01-25 18:37                     ` Zeng, Oak
2024-01-26 13:23                     ` Christian König
2024-01-26 13:23                       ` Christian König
2024-01-25 16:42               ` Zeng, Oak
2024-01-25 16:42                 ` Zeng, Oak
2024-01-25 18:32               ` Daniel Vetter
2024-01-25 18:32                 ` Daniel Vetter
2024-01-25 21:02                 ` Zeng, Oak
2024-01-25 21:02                   ` Zeng, Oak
2024-01-26  8:21                 ` Thomas Hellström
2024-01-26  8:21                   ` Thomas Hellström
2024-01-26 12:52                   ` Christian König
2024-01-26 12:52                     ` Christian König
2024-01-27  2:21                     ` Zeng, Oak
2024-01-27  2:21                       ` Zeng, Oak
2024-01-29 10:19                       ` Christian König
2024-01-29 10:19                         ` Christian König
2024-01-30  0:21                         ` Zeng, Oak
2024-01-30  0:21                           ` Zeng, Oak
2024-01-30  8:39                           ` Christian König
2024-01-30  8:39                             ` Christian König
2024-01-30 22:29                             ` Zeng, Oak
2024-01-30 22:29                               ` Zeng, Oak
2024-01-30 23:12                               ` David Airlie
2024-01-30 23:12                                 ` David Airlie
2024-01-31  9:15                                 ` Daniel Vetter
2024-01-31  9:15                                   ` Daniel Vetter
2024-01-31 20:17                                   ` Zeng, Oak
2024-01-31 20:17                                     ` Zeng, Oak
2024-01-31 20:59                                     ` Zeng, Oak
2024-01-31 20:59                                       ` Zeng, Oak
2024-02-01  8:52                                     ` Christian König
2024-02-01  8:52                                       ` Christian König
2024-02-29 18:22                                       ` Zeng, Oak
2024-03-08  4:43                                         ` Zeng, Oak
2024-03-08 10:07                                           ` Christian König
2024-01-30  8:43                           ` Thomas Hellström
2024-01-30  8:43                             ` Thomas Hellström
2024-01-29 15:03                 ` Felix Kuehling
2024-01-29 15:03                   ` Felix Kuehling
2024-01-29 15:33                   ` Christian König
2024-01-29 15:33                     ` Christian König
2024-01-29 16:24                     ` Felix Kuehling
2024-01-29 16:24                       ` Felix Kuehling
2024-01-29 16:28                       ` Christian König
2024-01-29 16:28                         ` Christian König
2024-01-29 17:52                         ` Felix Kuehling
2024-01-29 17:52                           ` Felix Kuehling
2024-01-29 19:03                           ` Christian König
2024-01-29 19:03                             ` Christian König
2024-01-29 20:24                             ` Felix Kuehling
2024-01-29 20:24                               ` Felix Kuehling
2024-02-23 20:12               ` Zeng, Oak
2024-02-27  6:54                 ` Christian König
2024-02-27 15:58                   ` Zeng, Oak
2024-02-28 19:51                     ` Zeng, Oak
2024-02-29  9:41                       ` Christian König
2024-02-29 16:05                         ` Zeng, Oak
2024-02-29 17:12                         ` Thomas Hellström
2024-03-01  7:01                           ` Christian König
2024-01-17 22:12 ` [PATCH 22/23] drm/xe/svm: Add DRM_XE_SVM kernel config entry Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-17 22:12 ` [PATCH 23/23] drm/xe/svm: Add svm memory hints interface Oak Zeng
2024-01-17 22:12   ` Oak Zeng
2024-01-18  2:45 ` ✓ CI.Patch_applied: success for XeKmd basic SVM support Patchwork
2024-01-18  2:46 ` ✗ CI.checkpatch: warning " Patchwork
2024-01-18  2:46 ` ✗ CI.KUnit: failure " Patchwork

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240409172418.GA5383@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=Thomas.Hellstrom@linux.intel.com \
    --cc=brian.welty@intel.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=himal.prasad.ghimiray@intel.com \
    --cc=intel-xe@lists.freedesktop.org \
    --cc=krishnaiah.bommu@intel.com \
    --cc=leon@kernel.org \
    --cc=matthew.brost@intel.com \
    --cc=niranjana.vishwanathapura@intel.com \
    --cc=oak.zeng@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.