From: "André Almeida" <andrealmeid@igalia.com>
To: Pekka Paalanen <ppaalanen@gmail.com>
Cc: dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
linux-kernel@vger.kernel.org, kernel-dev@igalia.com,
alexander.deucher@amd.com, christian.koenig@amd.com,
pierre-eric.pelloux-prayer@amd.com,
"Simon Ser" <contact@emersion.fr>,
"Rob Clark" <robdclark@gmail.com>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Daniel Stone" <daniel@fooishbar.org>,
"'Marek Olšák'" <maraeo@gmail.com>,
"Dave Airlie" <airlied@gmail.com>,
"Michel Dänzer" <michel.daenzer@mailbox.org>,
"Samuel Pitoiset" <samuel.pitoiset@gmail.com>,
"Timur Kristóf" <timur.kristof@gmail.com>,
"Bas Nieuwenhuizen" <bas@basnieuwenhuizen.nl>
Subject: Re: [RFC PATCH v3 2/4] drm: Create DRM_IOCTL_GET_RESET
Date: Wed, 21 Jun 2023 13:33:56 -0300 [thread overview]
Message-ID: <ab9ebe98-f583-234d-4901-ae570fb89d9f@igalia.com> (raw)
In-Reply-To: <20230621110931.6f3c8914@eldfell>
Em 21/06/2023 05:09, Pekka Paalanen escreveu:
> On Tue, 20 Jun 2023 21:57:17 -0300
> André Almeida <andrealmeid@igalia.com> wrote:
>
>> Create a new DRM ioctl operation to get the numbers of resets for a
>> given context. The numbers reflect just the resets that happened after
>> the context was created, and not since the machine was booted.
>>
>> Create a debugfs interface to make easier to test the API without real
>> resets.
>>
>> Signed-off-by: André Almeida <andrealmeid@igalia.com>
>> ---
>> drivers/gpu/drm/drm_debugfs.c | 2 ++
>> drivers/gpu/drm/drm_ioctl.c | 58 +++++++++++++++++++++++++++++++++++
>> include/drm/drm_device.h | 3 ++
>> include/drm/drm_drv.h | 3 ++
>> include/uapi/drm/drm.h | 21 +++++++++++++
>> include/uapi/drm/drm_mode.h | 15 +++++++++
>> 6 files changed, 102 insertions(+)
>
> ...
>
>> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
>> index a87bbbbca2d4..a84559aa0d77 100644
>> --- a/include/uapi/drm/drm.h
>> +++ b/include/uapi/drm/drm.h
>> @@ -1169,6 +1169,27 @@ extern "C" {
>> */
>> #define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2)
>>
>> +/**
>> + * DRM_IOCTL_GET_RESET - Get information about device resets
>> + *
>> + * This operation requests from the device information about resets. It should
>> + * consider only resets that happens after the context is created, therefore,
>> + * the counter should be zero during context creation.
>> + *
>> + * dev_reset_count tells how many resets have happened on this device, and
>> + * ctx_reset_count tells how many of such resets were caused by this context.
>> + *
>> + * Flags can be used to tell if a reset is in progress, and userspace should
>> + * wait until it's not in progress anymore to be able to create a new context;
>> + * and to tell if the VRAM is considered lost. There's no safe way to clean this
>> + * flag so if a context see this flag set, it should be like that until the end
>> + * of the context.
>
> Is "this flag" the VRAM_LOST? Or any flag?
>
> Does this mean that not all resets are fatal to the context? Is there
> any kind of reset that should not be fatal to a context? All the
> rendering APIs seem to assume that any reset is fatal and the context
> must be destroyed.
I got this flag from the `AMDGPU_CTX_OP_QUERY_STATE2` operation, and
it's used to notify that the reset was fatal for a giving context,
although the idea of non-fatal resets seems to be a bit controversial
for now, so I think it will be better if I leave this flag for latter
improvements of the API.
>
>> + */
>> +#define DRM_IOCTL_GET_RESET DRM_IOWR(0xCF, struct drm_get_reset)
>> +
>> +#define DRM_RESET_IN_PROGRESS 0x1
>> +#define DRM_RESET_VRAM_LOST 0x2
>
> Ok, so the dmabuf lost is being communicated here, but how would a
> userspace process know on which device a dmabuf resides on?
>
> Let's assume process A uses device 1 to draw, exports a dmabuf, sends
> it to process B which imports it to device 2. Device 1 resets and loses
> VRAM contents. How would process B notice that the dmabuf is lost when
> it never touches device 1 itself?
>
>> +
>> /*
>> * Device specific ioctls should only be in their respective headers
>> * The device specific ioctl range is from 0x40 to 0x9f.
>> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
>> index 43691058d28f..c3257bd1af9c 100644
>> --- a/include/uapi/drm/drm_mode.h
>> +++ b/include/uapi/drm/drm_mode.h
>> @@ -1308,6 +1308,21 @@ struct drm_mode_rect {
>> __s32 y2;
>> };
>>
>> +/**
>> + * struct drm_get_reset - Get information about a DRM device resets
>> + * @ctx_id: the context id to be queried about resets
>> + * @flags: flags
>> + * @dev_reset_count: global counter of resets for a given DRM device
>> + * @ctx_reset_count: of all the resets counted by this device, how many were
>> + * caused by this context.
>> + */
>> +struct drm_get_reset {
>> + __u32 ctx_id;
>> + __u32 flags;
>> + __u64 dev_reset_count;
>> + __u64 ctx_reset_count;
>> +};
>> +
>> #if defined(__cplusplus)
>> }
>> #endif
>
> Thanks,
> pq
next prev parent reply other threads:[~2023-06-21 16:35 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-21 0:57 [RFC PATCH v3 0/4] drm: Standardize device reset notification André Almeida
2023-06-21 0:57 ` [RFC PATCH v3 1/4] drm/doc: Document DRM device reset expectations André Almeida
2023-06-21 7:58 ` Pekka Paalanen
2023-06-21 16:28 ` André Almeida
2023-06-22 8:12 ` Pekka Paalanen
2023-06-26 16:15 ` André Almeida
2023-06-21 0:57 ` [RFC PATCH v3 2/4] drm: Create DRM_IOCTL_GET_RESET André Almeida
2023-06-21 8:09 ` Pekka Paalanen
2023-06-21 16:33 ` André Almeida [this message]
2023-06-22 8:22 ` Pekka Paalanen
2023-06-22 9:59 ` Christian König
2023-06-21 0:57 ` [RFC PATCH v3 3/4] drm/amdgpu: Implement DRM_IOCTL_GET_RESET André Almeida
2023-06-21 7:40 ` Christian König
2023-06-21 16:38 ` André Almeida
2023-06-22 7:45 ` Christian König
2023-06-21 0:57 ` [RFC PATCH v3 4/4] drm/i915: " André Almeida
2023-06-21 7:38 ` Jani Nikula
2023-06-21 7:42 ` [RFC PATCH v3 0/4] drm: Standardize device reset notification Christian König
2023-06-21 15:06 ` André Almeida
2023-06-21 15:09 ` Christian König
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