All of lore.kernel.org
 help / color / mirror / Atom feed
From: Zack Rusin <zackr@vmware.com>
To: "Christian König" <christian.koenig@amd.com>
Cc: DRI Development <dri-devel@lists.freedesktop.org>,
	Huang Rui <ray.huang@amd.com>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH] drm/ttm: Don't delete the system manager before the delayed delete
Date: Thu, 23 Sep 2021 09:53:58 -0400	[thread overview]
Message-ID: <d78057b6-d577-d908-8b87-baf980bd86fd@vmware.com> (raw)
In-Reply-To: <6F174F23-797F-4106-BE54-E208FA7571B5@vmware.com>

On 9/20/21 10:59 AM, Zack Rusin wrote:
>> On Sep 20, 2021, at 02:30, Christian König <christian.koenig@amd.com> wrote:
>>
>> Am 17.09.21 um 19:53 schrieb Zack Rusin:
>>> On some hardware, in particular in virtualized environments, the
>>> system memory can be shared with the "hardware". In those cases
>>> the BO's allocated through the ttm system manager might be
>>> busy during ttm_bo_put which results in them being scheduled
>>> for a delayed deletion.
>>
>> While the patch itself is probably fine the reasoning here is a clear NAK.
>>
>> Buffers in the system domain are not GPU accessible by definition, even in a shared environment and so *must* be idle.
> 
> I’m assuming that means they are not allowed to be ever fenced then, yes?

Any thoughts on this? I'd love a confirmation because it would mean I need to go and rewrite the vmwgfx_mob.c bits where we use TTM_PL_SYSTEM memory (through vmw_bo_create_and_populate) for a page table which is read by the host, and those bo's need to be fenced to prevent destruction of the page tables while the memory they point to is still used. So if those were never allowed to be fenced in the first place we probably need to add a new memory type to hold those page tables.

z

  reply	other threads:[~2021-09-23 13:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-17 17:53 [PATCH] drm/ttm: Don't delete the system manager before the delayed delete Zack Rusin
2021-09-17 18:34 ` Andrey Grodzovsky
2021-09-20  6:30 ` Christian König
2021-09-20 14:59   ` Zack Rusin
2021-09-23 13:53     ` Zack Rusin [this message]
2021-09-23 14:49       ` Christian König

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=d78057b6-d577-d908-8b87-baf980bd86fd@vmware.com \
    --to=zackr@vmware.com \
    --cc=airlied@linux.ie \
    --cc=christian.koenig@amd.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=ray.huang@amd.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.