All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org,
	linux-media@vger.kernel.org, intel-gfx@lists.freedesktop.org
Cc: daniel@ffwll.ch
Subject: Re: [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl
Date: Tue, 21 Sep 2021 11:41:52 +0200	[thread overview]
Message-ID: <64b6a924-be38-0ed0-da92-86296702f71c@gmail.com> (raw)
In-Reply-To: <563bb7c3-f956-212d-6085-b1b88292887c@linux.intel.com>

Am 20.09.21 um 12:33 schrieb Tvrtko Ursulin:
> On 20/09/2021 11:13, Christian König wrote:
>> Am 20.09.21 um 10:45 schrieb Tvrtko Ursulin:
>>>
>>> On 17/09/2021 13:35, Christian König wrote:
>>>> This makes the function much simpler since the complex
>>>> retry logic is now handled else where.
>>>>
>>>> Signed-off-by: Christian König <christian.koenig@amd.com>
>>>> ---
>>>>   drivers/gpu/drm/i915/gem/i915_gem_busy.c | 32 
>>>> ++++++++----------------
>>>>   1 file changed, 11 insertions(+), 21 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c 
>>>> b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
>>>> index 6234e17259c1..b1cb7ba688da 100644
>>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
>>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
>>>> @@ -82,8 +82,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void 
>>>> *data,
>>>>   {
>>>>       struct drm_i915_gem_busy *args = data;
>>>>       struct drm_i915_gem_object *obj;
>>>> -    struct dma_resv_list *list;
>>>> -    unsigned int seq;
>>>> +    struct dma_resv_iter cursor;
>>>> +    struct dma_fence *fence;
>>>>       int err;
>>>>         err = -ENOENT;
>>>> @@ -109,27 +109,17 @@ i915_gem_busy_ioctl(struct drm_device *dev, 
>>>> void *data,
>>>>        * to report the overall busyness. This is what the 
>>>> wait-ioctl does.
>>>>        *
>>>>        */
>>>> -retry:
>>>> -    seq = raw_read_seqcount(&obj->base.resv->seq);
>>>> -
>>>> -    /* Translate the exclusive fence to the READ *and* WRITE 
>>>> engine */
>>>> -    args->busy = 
>>>> busy_check_writer(dma_resv_excl_fence(obj->base.resv));
>>>> -
>>>> -    /* Translate shared fences to READ set of engines */
>>>> -    list = dma_resv_shared_list(obj->base.resv);
>>>> -    if (list) {
>>>> -        unsigned int shared_count = list->shared_count, i;
>>>> -
>>>> -        for (i = 0; i < shared_count; ++i) {
>>>> -            struct dma_fence *fence =
>>>> -                rcu_dereference(list->shared[i]);
>>>> -
>>>> +    args->busy = false;
>>>> +    dma_resv_iter_begin(&cursor, obj->base.resv, true);
>>>> +    dma_resv_for_each_fence_unlocked(&cursor, fence) {
>>>
>>> You did not agree with my suggestion to reset args->busy on restart 
>>> and so preserve current behaviour?
>>
>> No, I want to keep the restart behavior internally to the dma_resv 
>> object and as far as I can see it should not make a difference here.
>
> To be clear, on paper difference between old and new implementation is 
> if the restart happens while processing the shared fences.
>
> Old implementation unconditionally goes to "args->busy =
> >>> busy_check_writer(dma_resv_excl_fence(obj->base.resv));" and so 
> overwrites the set of flags returned to userspace.
>
> New implementation can merge new read flags to the old set of flags 
> and so return a composition of past and current fences.
>
> Maybe it does not matter hugely in this case, depends if userspace 
> typically just restarts until flags are clear. But I am not sure.
>
> On the higher level - what do you mean with wanting to keep the 
> restart behaviour internal? Not providing iterators users means of 
> detecting it? I think it has to be provided.

Ok I will adjust that for now to get the patch set upstream. But in 
general when somebody outside of the dma_resv code base depends on the 
restart behavior then that's a bug inside the design of that code.

The callers should only care about what unsignaled fences are inside the 
dma_resv container and it shouldn't matter if those fences are presented 
once or multiple times because of a reset..

When this makes a difference we have a bug in the handling and should 
probably consider taking the dma_resv.lock instead.

Regards,
Christian.

>
> Regards,
>
> Tvrtko
>
>> Regards,
>> Christian.
>>
>>>
>>> Regards,
>>>
>>> Tvrtko
>>>
>>>> +        if (dma_resv_iter_is_exclusive(&cursor))
>>>> +            /* Translate the exclusive fence to the READ *and* 
>>>> WRITE engine */
>>>> +            args->busy = busy_check_writer(fence);
>>>> +        else
>>>> +            /* Translate shared fences to READ set of engines */
>>>>               args->busy |= busy_check_reader(fence);
>>>> -        }
>>>>       }
>>>> -
>>>> -    if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq))
>>>> -        goto retry;
>>>> +    dma_resv_iter_end(&cursor);
>>>>         err = 0;
>>>>   out:
>>>>
>>


  reply	other threads:[~2021-09-21  9:41 UTC|newest]

Thread overview: 126+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-17 12:34 Deploying new iterator interface for dma-buf Christian König
2021-09-17 12:34 ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 01/26] dma-buf: add dma_resv_for_each_fence_unlocked v2 Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 13:23   ` Daniel Vetter
2021-09-17 13:23     ` [Intel-gfx] " Daniel Vetter
2021-09-20  8:43     ` Tvrtko Ursulin
2021-09-20 10:09       ` Christian König
2021-09-20 10:26         ` Tvrtko Ursulin
2021-09-17 12:34 ` [PATCH 02/26] dma-buf: add dma_resv_for_each_fence Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 13:27   ` Daniel Vetter
2021-09-17 13:27     ` [Intel-gfx] " Daniel Vetter
2021-09-17 14:30     ` Daniel Vetter
2021-09-17 14:30       ` Daniel Vetter
2021-09-17 12:34 ` [PATCH 03/26] dma-buf: use new iterator in dma_resv_copy_fences Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:35   ` Daniel Vetter
2021-09-17 14:35     ` [Intel-gfx] " Daniel Vetter
2021-09-20  7:23     ` Christian König
2021-09-20  7:23       ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 04/26] dma-buf: use new iterator in dma_resv_get_fences v2 Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:39   ` Daniel Vetter
2021-09-17 14:39     ` [Intel-gfx] " Daniel Vetter
2021-09-17 12:34 ` [PATCH 05/26] dma-buf: use new iterator in dma_resv_wait_timeout Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:43   ` Daniel Vetter
2021-09-17 14:43     ` [Intel-gfx] " Daniel Vetter
2021-09-20  7:27     ` Christian König
2021-09-20  7:27       ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 06/26] dma-buf: use new iterator in dma_resv_test_signaled Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:45   ` Daniel Vetter
2021-09-17 14:45     ` [Intel-gfx] " Daniel Vetter
2021-09-17 12:34 ` [PATCH 07/26] drm/ttm: use the new iterator in ttm_bo_flush_all_fences Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:50   ` Daniel Vetter
2021-09-17 14:50     ` [Intel-gfx] " Daniel Vetter
2021-09-17 12:34 ` [PATCH 08/26] drm/amdgpu: use the new iterator in amdgpu_sync_resv Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 09/26] drm/amdgpu: use new iterator in amdgpu_ttm_bo_eviction_valuable Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 10/26] drm/msm: use new iterator in msm_gem_describe Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 11/26] drm/radeon: use new iterator in radeon_sync_resv Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 12:34 ` [PATCH 12/26] drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2 Christian König
2021-09-17 12:34   ` [Intel-gfx] " Christian König
2021-09-17 14:52   ` Daniel Vetter
2021-09-17 14:52     ` [Intel-gfx] " Daniel Vetter
2021-11-15 14:03   ` Sascha Hauer
2021-11-15 14:03     ` Sascha Hauer
2021-11-15 14:03     ` [Intel-gfx] " Sascha Hauer
2021-11-15 14:08     ` Daniel Vetter
2021-11-15 14:08       ` [Intel-gfx] " Daniel Vetter
2021-11-15 14:08       ` Daniel Vetter
2021-11-15 20:32       ` Christian König
2021-11-15 20:32         ` Christian König
2021-11-15 20:32         ` [Intel-gfx] " Christian König
2021-11-16  7:56       ` Sascha Hauer
2021-11-16  7:56         ` [Intel-gfx] " Sascha Hauer
2021-11-16  7:56         ` Sascha Hauer
2021-09-17 12:35 ` [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-20  8:45   ` Tvrtko Ursulin
2021-09-20 10:13     ` Christian König
2021-09-20 10:33       ` Tvrtko Ursulin
2021-09-21  9:41         ` Christian König [this message]
2021-09-21 13:10           ` Tvrtko Ursulin
2021-09-17 12:35 ` [PATCH 14/26] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-20  8:45   ` Tvrtko Ursulin
2021-09-20  8:47     ` Tvrtko Ursulin
2021-09-20 10:14       ` Christian König
2021-09-17 12:35 ` [PATCH 15/26] drm/i915: use the new iterator in i915_request_await_object v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 16/26] drm/i915: use new iterator in i915_gem_object_wait_reservation v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-20 10:00   ` Tvrtko Ursulin
2021-09-21 17:35     ` Christian König
2021-09-17 12:35 ` [PATCH 17/26] drm/i915: use new iterator in i915_gem_object_wait_priority v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 18/26] drm/i915: use new iterator in i915_gem_object_last_write_engine v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 19/26] drm/i915: use new cursor in intel_prepare_plane_fb v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 20/26] drm: use new iterator in drm_gem_fence_array_add_implicit v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 14:53   ` Daniel Vetter
2021-09-17 14:53     ` [Intel-gfx] " Daniel Vetter
2021-09-20  7:31     ` Christian König
2021-09-20  7:31       ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 21/26] drm: use new iterator in drm_gem_plane_helper_prepare_fb v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 14:55   ` Daniel Vetter
2021-09-17 14:55     ` [Intel-gfx] " Daniel Vetter
2021-09-20  7:35     ` Christian König
2021-09-20  7:35       ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 22/26] drm/nouveau: use the new iterator in nouveau_fence_sync Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 23/26] drm/nouveau: use the new interator in nv50_wndw_prepare_fb v2 Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 24/26] drm/etnaviv: use new iterator in etnaviv_gem_describe Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 25/26] drm/etnaviv: replace dma_resv_get_excl_unlocked Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 12:35 ` [PATCH 26/26] dma-buf: nuke dma_resv_get_excl_unlocked Christian König
2021-09-17 12:35   ` [Intel-gfx] " Christian König
2021-09-17 14:56   ` Daniel Vetter
2021-09-17 14:56     ` [Intel-gfx] " Daniel Vetter
2021-09-17 14:01 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [01/26] dma-buf: add dma_resv_for_each_fence_unlocked v2 Patchwork
2021-09-17 14:29 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2021-09-17 15:43 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
  -- strict thread matches above, loose matches on Subject: below --
2021-09-22  9:10 Deploying new iterator interface for dma-buf Christian König
2021-09-22  9:10 ` [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl Christian König
2021-09-22 10:21   ` Tvrtko Ursulin
2021-09-22 11:46     ` Tvrtko Ursulin
2021-09-22 12:15       ` Christian König
2021-09-22 12:20         ` Tvrtko Ursulin
2021-09-22 12:22           ` Christian König
2021-09-22 14:31     ` Christian König
2021-09-22 14:39       ` Tvrtko Ursulin
2021-09-21 17:36 [PATCH 01/26] dma-buf: add dma_resv_for_each_fence_unlocked v3 Christian König
2021-09-21 17:36 ` [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl Christian König
2021-09-16 11:30 Deploying new iterator interface for dma-buf Christian König
2021-09-16 11:30 ` [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl Christian König
2021-09-13 13:16 Deploying new iterator interface for dma-buf Christian König
2021-09-13 13:16 ` [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl Christian König
2021-09-14 13:18   ` Tvrtko Ursulin

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=64b6a924-be38-0ed0-da92-86296702f71c@gmail.com \
    --to=ckoenig.leichtzumerken@gmail.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=linaro-mm-sig@lists.linaro.org \
    --cc=linux-media@vger.kernel.org \
    --cc=tvrtko.ursulin@linux.intel.com \
    --subject='Re: [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl' \
    /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

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.