From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Rob Clark <robdclark@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
open list <linux-kernel@vger.kernel.org>,
Daniel Vetter <daniel@ffwll.ch>, Will Deacon <will@kernel.org>,
David Airlie <airlied@linux.ie>,
linux-arm-msm@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
Robin Murphy <robin.murphy@arm.com>,
dri-devel@lists.freedesktop.org,
Stephen Boyd <swboyd@chromium.org>, Sean Paul <sean@poorly.run>,
iommu@lists.linux-foundation.org,
Sibi Sankar <sibis@codeaurora.org>,
Vivek Gautam <vivek.gautam@codeaurora.org>,
freedreno@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 01/19] drm/msm: remove dangling submitqueue references
Date: Tue, 1 Sep 2020 02:35:17 +0000 [thread overview]
Message-ID: <20200901023517.GA54956@uller> (raw)
In-Reply-To: <20200814024114.1177553-2-robdclark@gmail.com>
On Fri 14 Aug 02:40 UTC 2020, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
>
> Currently it doesn't matter, since we free the ctx immediately. But
> when we start refcnt'ing the ctx, we don't want old dangling list
> entries to hang around.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
> drivers/gpu/drm/msm/msm_submitqueue.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
> index a1d94be7883a..90c9d84e6155 100644
> --- a/drivers/gpu/drm/msm/msm_submitqueue.c
> +++ b/drivers/gpu/drm/msm/msm_submitqueue.c
> @@ -49,8 +49,10 @@ void msm_submitqueue_close(struct msm_file_private *ctx)
> * No lock needed in close and there won't
> * be any more user ioctls coming our way
> */
> - list_for_each_entry_safe(entry, tmp, &ctx->submitqueues, node)
> + list_for_each_entry_safe(entry, tmp, &ctx->submitqueues, node) {
> + list_del(&entry->node);
If you refcount ctx, what does that do for the entries in the submit
queue?
"entry" here is kref'ed, but you're popping it off the list regardless
of the put ends up freeing the object or not - which afaict would mean
leaking the object.
On the other hand, with the current implementation an object with higher
refcount with adjacent objects of single refcount would end up with
dangling pointers after the put. So in itself this change seems like a
net gain, but I'm wondering about the plan described in the commit
message.
Regards,
Bjorn
> msm_submitqueue_put(entry);
> + }
> }
>
> int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
> --
> 2.26.2
>
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next prev parent reply other threads:[~2020-09-01 2:36 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-10 22:26 [PATCH v12 00/13] iommu/arm-smmu: Add Adreno SMMU specific implementation Jordan Crouse
2020-08-10 22:26 ` [PATCH v12 01/13] iommu/arm-smmu: Pass io-pgtable config to implementation specific function Jordan Crouse
2020-08-10 22:26 ` [PATCH v12 02/13] iommu/arm-smmu: Add support for split pagetables Jordan Crouse
2020-08-10 22:26 ` [PATCH v12 03/13] iommu/arm-smmu: Prepare for the adreno-smmu implementation Jordan Crouse
2020-08-10 22:26 ` [PATCH v12 05/13] iommu/arm-smmu-qcom: Add implementation for the adreno GPU SMMU Jordan Crouse
2020-08-13 13:23 ` Will Deacon
2020-08-10 22:26 ` [PATCH v12 06/13] dt-bindings: arm-smmu: Add compatible string for Adreno " Jordan Crouse
2020-08-10 22:26 ` [RFC v12 13/13] iommu/arm-smmu: Add a init_context_bank implementation hook Jordan Crouse
2020-08-13 13:03 ` Will Deacon
2020-08-13 13:19 ` [PATCH v12 00/13] iommu/arm-smmu: Add Adreno SMMU specific implementation Will Deacon
2020-08-14 2:40 ` [PATCH 00/19] iommu/arm-smmu + drm/msm: per-process GPU pgtables Rob Clark
2020-08-17 16:51 ` Jordan Crouse
2020-08-14 2:40 ` [PATCH 01/19] drm/msm: remove dangling submitqueue references Rob Clark
2020-08-17 16:51 ` Jordan Crouse
2020-09-01 2:35 ` Bjorn Andersson [this message]
2020-09-01 3:42 ` Rob Clark
2020-09-01 5:42 ` Bjorn Andersson
2020-09-01 5:42 ` Bjorn Andersson
2020-08-14 2:40 ` [PATCH 02/19] iommu/arm-smmu: Pass io-pgtable config to implementation specific function Rob Clark
2020-09-01 3:36 ` Bjorn Andersson
2020-08-14 2:40 ` [PATCH 03/19] iommu/arm-smmu: Add support for split pagetables Rob Clark
2020-09-01 3:41 ` Bjorn Andersson
2020-08-14 2:40 ` [PATCH 04/19] iommu/arm-smmu: Prepare for the adreno-smmu implementation Rob Clark
2020-08-14 2:41 ` [PATCH 05/19] iommu: add private interface for adreno-smmu Rob Clark
2020-08-17 16:52 ` [Freedreno] " Jordan Crouse
2020-09-01 3:52 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 06/19] drm/msm/gpu: add dev_to_gpu() helper Rob Clark
2020-08-17 16:53 ` [Freedreno] " Jordan Crouse
2020-09-01 4:32 ` Bjorn Andersson
2020-09-01 15:53 ` Rob Clark
2020-08-14 2:41 ` [PATCH 07/19] drm/msm: set adreno_smmu as gpu's drvdata Rob Clark
2020-08-17 16:55 ` Jordan Crouse
2020-09-01 4:58 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 08/19] iommu/arm-smmu: constify some helpers Rob Clark
2020-09-01 4:56 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 09/19] iommu/arm-smmu-qcom: Add implementation for the adreno GPU SMMU Rob Clark
2020-09-01 5:00 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 10/19] dt-bindings: arm-smmu: Add compatible string for Adreno " Rob Clark
2020-09-01 5:00 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 11/19] drm/msm: Add a context pointer to the submitqueue Rob Clark
2020-09-01 5:05 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 12/19] drm/msm: Drop context arg to gpu->submit() Rob Clark
2020-09-01 5:06 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 13/19] drm/msm: Set the global virtual address range from the IOMMU domain Rob Clark
2020-09-01 5:23 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 14/19] drm/msm: Add support to create a local pagetable Rob Clark
2020-09-01 5:28 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 15/19] drm/msm: Add support for private address space instances Rob Clark
2020-09-01 5:30 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 16/19] drm/msm/a6xx: Add support for per-instance pagetables Rob Clark
2020-08-17 15:40 ` Akhil P Oommen
2020-08-17 15:51 ` Rob Clark
2020-08-17 16:47 ` Jordan Crouse
2020-08-14 2:41 ` [PATCH 17/19] arm: dts: qcom: sm845: Set the compatible string for the GPU SMMU Rob Clark
2020-08-14 2:41 ` [PATCH 18/19] iommu/arm-smmu: add a way for implementations to influence SCTLR Rob Clark
2020-09-01 5:31 ` Bjorn Andersson
2020-08-14 2:41 ` [PATCH 19/19] drm/msm: show process names in gem_describe Rob Clark
2020-08-17 17:14 ` [Freedreno] " Jordan Crouse
2020-09-01 5:35 ` Bjorn Andersson
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