From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: "Daniel Vetter" <daniel@ffwll.ch>,
"Thomas Hellström (VMware)" <thomas_os@shipmail.org>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [PATCH 5/5] drm/amdgpu: implement amdgpu_gem_prime_move_notify v2
Date: Sun, 23 Feb 2020 16:45:13 +0100 [thread overview]
Message-ID: <d9343617-9da8-5fea-a0f1-99db34a0cf2c@gmail.com> (raw)
In-Reply-To: <20200221171217.GD2363188@phenom.ffwll.local>
Am 21.02.20 um 18:12 schrieb Daniel Vetter:
> [SNIP]
> Yeah the Great Plan (tm) is to fully rely on ww_mutex slowly degenerating
> into essentially a global lock. But only when there's actual contention
> and thrashing.
Yes exactly. A really big problem in TTM is currently that we drop the
lock after evicting BOs because they tend to move in again directly
after that.
From practice I can also confirm that there is exactly zero benefit
from dropping locks early and reacquire them for example for the VM page
tables. That's just makes it more likely that somebody needs to roll
back and this is what we need to avoid in the first place.
Contention on BO locks during command submission is perfectly fine as
long as this is as lightweight as possible while we don't have trashing.
When we have trashing multi submission performance is best archived to
just favor a single process to finish its business and block everybody else.
Because of this I would actually vote for forbidding to release
individual ww_mutex() locks in a context.
Regards,
Christian.
> -Daniel
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: "Daniel Vetter" <daniel@ffwll.ch>,
"Thomas Hellström (VMware)" <thomas_os@shipmail.org>
Cc: "moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
intel-gfx <intel-gfx@lists.freedesktop.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [PATCH 5/5] drm/amdgpu: implement amdgpu_gem_prime_move_notify v2
Date: Sun, 23 Feb 2020 16:45:13 +0100 [thread overview]
Message-ID: <d9343617-9da8-5fea-a0f1-99db34a0cf2c@gmail.com> (raw)
In-Reply-To: <20200221171217.GD2363188@phenom.ffwll.local>
Am 21.02.20 um 18:12 schrieb Daniel Vetter:
> [SNIP]
> Yeah the Great Plan (tm) is to fully rely on ww_mutex slowly degenerating
> into essentially a global lock. But only when there's actual contention
> and thrashing.
Yes exactly. A really big problem in TTM is currently that we drop the
lock after evicting BOs because they tend to move in again directly
after that.
From practice I can also confirm that there is exactly zero benefit
from dropping locks early and reacquire them for example for the VM page
tables. That's just makes it more likely that somebody needs to roll
back and this is what we need to avoid in the first place.
Contention on BO locks during command submission is perfectly fine as
long as this is as lightweight as possible while we don't have trashing.
When we have trashing multi submission performance is best archived to
just favor a single process to finish its business and block everybody else.
Because of this I would actually vote for forbidding to release
individual ww_mutex() locks in a context.
Regards,
Christian.
> -Daniel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: "Daniel Vetter" <daniel@ffwll.ch>,
"Thomas Hellström (VMware)" <thomas_os@shipmail.org>
Cc: "moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
intel-gfx <intel-gfx@lists.freedesktop.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [Intel-gfx] [PATCH 5/5] drm/amdgpu: implement amdgpu_gem_prime_move_notify v2
Date: Sun, 23 Feb 2020 16:45:13 +0100 [thread overview]
Message-ID: <d9343617-9da8-5fea-a0f1-99db34a0cf2c@gmail.com> (raw)
In-Reply-To: <20200221171217.GD2363188@phenom.ffwll.local>
Am 21.02.20 um 18:12 schrieb Daniel Vetter:
> [SNIP]
> Yeah the Great Plan (tm) is to fully rely on ww_mutex slowly degenerating
> into essentially a global lock. But only when there's actual contention
> and thrashing.
Yes exactly. A really big problem in TTM is currently that we drop the
lock after evicting BOs because they tend to move in again directly
after that.
From practice I can also confirm that there is exactly zero benefit
from dropping locks early and reacquire them for example for the VM page
tables. That's just makes it more likely that somebody needs to roll
back and this is what we need to avoid in the first place.
Contention on BO locks during command submission is perfectly fine as
long as this is as lightweight as possible while we don't have trashing.
When we have trashing multi submission performance is best archived to
just favor a single process to finish its business and block everybody else.
Because of this I would actually vote for forbidding to release
individual ww_mutex() locks in a context.
Regards,
Christian.
> -Daniel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2020-02-23 15:45 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-17 15:45 RFC: Unpinned DMA-buf handling Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 15:45 ` [PATCH 1/5] dma-buf: add dynamic DMA-buf handling v14 Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 15:50 ` Christian König
2020-02-17 15:50 ` [Intel-gfx] " Christian König
2020-02-17 15:50 ` Christian König
2020-02-17 15:45 ` [PATCH 2/5] drm/ttm: remove the backing store if no placement is given Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 15:45 ` [PATCH 3/5] drm/amdgpu: use allowed_domains for exported DMA-bufs Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 15:45 ` [PATCH 4/5] drm/amdgpu: add amdgpu_dma_buf_pin/unpin v2 Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 15:45 ` [PATCH 5/5] drm/amdgpu: implement amdgpu_gem_prime_move_notify v2 Christian König
2020-02-17 15:45 ` [Intel-gfx] " Christian König
2020-02-17 15:45 ` Christian König
2020-02-17 17:55 ` Daniel Vetter
2020-02-17 17:55 ` [Intel-gfx] " Daniel Vetter
2020-02-17 17:55 ` Daniel Vetter
2020-02-17 18:58 ` Christian König
2020-02-17 18:58 ` [Intel-gfx] " Christian König
2020-02-17 18:58 ` Christian König
2020-02-17 19:38 ` Daniel Vetter
2020-02-17 19:38 ` [Intel-gfx] " Daniel Vetter
2020-02-17 19:38 ` Daniel Vetter
2020-02-18 10:42 ` Christian König
2020-02-18 10:42 ` [Intel-gfx] " Christian König
2020-02-18 20:17 ` Thomas Hellström (VMware)
2020-02-18 20:17 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-18 20:17 ` Thomas Hellström (VMware)
2020-02-18 21:01 ` Daniel Vetter
2020-02-18 21:01 ` [Intel-gfx] " Daniel Vetter
2020-02-18 21:01 ` Daniel Vetter
2020-02-19 6:42 ` Thomas Hellström (VMware)
2020-02-19 6:42 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-19 6:42 ` Thomas Hellström (VMware)
2020-02-20 9:39 ` Thomas Hellström (VMware)
2020-02-20 9:39 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-20 9:39 ` Thomas Hellström (VMware)
2020-02-20 18:04 ` Daniel Vetter
2020-02-20 18:04 ` [Intel-gfx] " Daniel Vetter
2020-02-20 18:04 ` Daniel Vetter
2020-02-20 19:46 ` Thomas Hellström (VMware)
2020-02-20 19:46 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-20 19:46 ` Thomas Hellström (VMware)
2020-02-20 20:08 ` Daniel Vetter
2020-02-20 20:08 ` [Intel-gfx] " Daniel Vetter
2020-02-20 20:08 ` Daniel Vetter
2020-02-20 22:51 ` Thomas Hellström (VMware)
2020-02-20 22:51 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-20 22:51 ` Thomas Hellström (VMware)
2020-02-21 17:12 ` Daniel Vetter
2020-02-21 17:12 ` [Intel-gfx] " Daniel Vetter
2020-02-21 17:12 ` Daniel Vetter
2020-02-21 19:45 ` Thomas Hellström (VMware)
2020-02-21 19:45 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-21 19:45 ` Thomas Hellström (VMware)
2020-02-23 15:45 ` Christian König [this message]
2020-02-23 15:45 ` [Intel-gfx] " Christian König
2020-02-23 15:45 ` Christian König
2020-02-23 16:54 ` Thomas Hellström (VMware)
2020-02-23 16:54 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-23 16:54 ` Thomas Hellström (VMware)
2020-02-24 18:46 ` Christian König
2020-02-24 18:46 ` [Intel-gfx] " Christian König
2020-02-24 18:46 ` Christian König
2020-02-24 21:11 ` Thomas Hellström (VMware)
2020-02-24 21:11 ` [Intel-gfx] " Thomas Hellström (VMware)
2020-02-24 21:11 ` Thomas Hellström (VMware)
2020-02-25 17:16 ` Daniel Vetter
2020-02-25 17:16 ` [Intel-gfx] " Daniel Vetter
2020-02-25 17:16 ` Daniel Vetter
2020-02-26 16:32 ` Daniel Vetter
2020-02-26 16:32 ` [Intel-gfx] " Daniel Vetter
2020-02-26 16:32 ` Daniel Vetter
2020-02-27 9:20 ` Christian König
2020-02-27 9:20 ` [Intel-gfx] " Christian König
2020-02-27 9:20 ` Christian König
2020-02-27 9:38 ` Daniel Vetter
2020-02-27 9:38 ` [Intel-gfx] " Daniel Vetter
2020-02-27 9:38 ` Daniel Vetter
2020-02-18 23:33 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [1/5] dma-buf: add dynamic DMA-buf handling v14 Patchwork
2020-02-19 0:06 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-02-20 11:41 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
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