From: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 5/5] drm/i915/gem: Silence sparse for RCU protection inside the constructor
Date: Fri, 15 Nov 2019 12:55:04 +0000 [thread overview]
Message-ID: <9e701baf-a597-222a-01fa-78f570518a39@linux.intel.com> (raw)
In-Reply-To: <20191114225736.616885-5-chris@chris-wilson.co.uk>
On 14/11/2019 22:57, Chris Wilson wrote:
> Inside the constructor, while cloning, we need to replace the
> dst->engines. Having forgotten that dst->engines is marked as RCU
> protected, we need to add the appropriate annotations to make sparse
> happy.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_context.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 1284f47303fa..6f1e6181f67a 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -2009,7 +2009,8 @@ static int clone_engines(struct i915_gem_context *dst,
> user_engines = i915_gem_context_user_engines(src);
> i915_gem_context_unlock_engines(src);
>
> - free_engines(dst->engines);
> + /* Serialised by constructor */
> + free_engines(__context_engines_static(dst));
> RCU_INIT_POINTER(dst->engines, clone);
> if (user_engines)
> i915_gem_context_set_user_engines(dst);
> @@ -2044,7 +2045,8 @@ static int clone_sseu(struct i915_gem_context *dst,
> unsigned long n;
> int err;
>
> - clone = dst->engines; /* no locking required; sole access */
> + /* no locking required; sole access under constructor*/
> + clone = __context_engines_static(dst);
> if (e->num_engines != clone->num_engines) {
> err = -EINVAL;
> goto unlock;
>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Regards,
Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
WARNING: multiple messages have this Message-ID (diff)
From: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>, intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 5/5] drm/i915/gem: Silence sparse for RCU protection inside the constructor
Date: Fri, 15 Nov 2019 12:55:04 +0000 [thread overview]
Message-ID: <9e701baf-a597-222a-01fa-78f570518a39@linux.intel.com> (raw)
Message-ID: <20191115125504.QjfqucajgyanRh_snCRNgdlDwjRgfDVVNg6l6yieTJk@z> (raw)
In-Reply-To: <20191114225736.616885-5-chris@chris-wilson.co.uk>
On 14/11/2019 22:57, Chris Wilson wrote:
> Inside the constructor, while cloning, we need to replace the
> dst->engines. Having forgotten that dst->engines is marked as RCU
> protected, we need to add the appropriate annotations to make sparse
> happy.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_context.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 1284f47303fa..6f1e6181f67a 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -2009,7 +2009,8 @@ static int clone_engines(struct i915_gem_context *dst,
> user_engines = i915_gem_context_user_engines(src);
> i915_gem_context_unlock_engines(src);
>
> - free_engines(dst->engines);
> + /* Serialised by constructor */
> + free_engines(__context_engines_static(dst));
> RCU_INIT_POINTER(dst->engines, clone);
> if (user_engines)
> i915_gem_context_set_user_engines(dst);
> @@ -2044,7 +2045,8 @@ static int clone_sseu(struct i915_gem_context *dst,
> unsigned long n;
> int err;
>
> - clone = dst->engines; /* no locking required; sole access */
> + /* no locking required; sole access under constructor*/
> + clone = __context_engines_static(dst);
> if (e->num_engines != clone->num_engines) {
> err = -EINVAL;
> goto unlock;
>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Regards,
Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2019-11-15 12:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 22:57 [PATCH 1/5] drm/i915/gt: Wait for new requests in intel_gt_retire_requests() Chris Wilson
2019-11-14 22:57 ` [Intel-gfx] " Chris Wilson
2019-11-14 22:57 ` [PATCH 2/5] drm/i915/selftests: Exercise rc6 handling Chris Wilson
2019-11-14 22:57 ` [Intel-gfx] " Chris Wilson
2019-11-14 22:57 ` [PATCH 3/5] drm/i915/selftests: Be explicit in ERR_PTR handling Chris Wilson
2019-11-14 22:57 ` [Intel-gfx] " Chris Wilson
2019-11-15 12:47 ` Tvrtko Ursulin
2019-11-15 12:47 ` [Intel-gfx] " Tvrtko Ursulin
2019-11-15 12:55 ` [PATCH] " Chris Wilson
2019-11-15 12:55 ` [Intel-gfx] " Chris Wilson
2019-11-14 22:57 ` [PATCH 4/5] drm/i915/selftests: Exercise long preemption chains Chris Wilson
2019-11-14 22:57 ` [Intel-gfx] " Chris Wilson
2019-11-15 12:50 ` Tvrtko Ursulin
2019-11-15 12:50 ` [Intel-gfx] " Tvrtko Ursulin
2019-11-14 22:57 ` [PATCH 5/5] drm/i915/gem: Silence sparse for RCU protection inside the constructor Chris Wilson
2019-11-14 22:57 ` [Intel-gfx] " Chris Wilson
2019-11-15 12:55 ` Tvrtko Ursulin [this message]
2019-11-15 12:55 ` Tvrtko Ursulin
2019-11-15 0:12 ` ✗ Fi.CI.CHECKPATCH: warning for series starting with [1/5] drm/i915/gt: Wait for new requests in intel_gt_retire_requests() Patchwork
2019-11-15 0:12 ` [Intel-gfx] " Patchwork
2019-11-15 0:34 ` ✓ Fi.CI.BAT: success " Patchwork
2019-11-15 0:34 ` [Intel-gfx] " Patchwork
2019-11-15 12:45 ` [PATCH 1/5] " Tvrtko Ursulin
2019-11-15 12:45 ` [Intel-gfx] " Tvrtko Ursulin
2019-11-15 12:49 ` Chris Wilson
2019-11-15 12:49 ` [Intel-gfx] " Chris Wilson
2019-11-15 12:56 ` Tvrtko Ursulin
2019-11-15 12:56 ` [Intel-gfx] " Tvrtko Ursulin
2019-11-15 17:18 ` ✗ Fi.CI.BUILD: failure for series starting with [1/5] drm/i915/gt: Wait for new requests in intel_gt_retire_requests() (rev2) Patchwork
2019-11-15 17:18 ` [Intel-gfx] " Patchwork
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