From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 1/4] drm/i915: Drop wmb() inside pread_gtt
Date: Thu, 18 Jul 2019 21:23:32 +0300 [thread overview]
Message-ID: <20190718182332.GF5942@intel.com> (raw)
In-Reply-To: <20190718145407.21352-1-chris@chris-wilson.co.uk>
On Thu, Jul 18, 2019 at 03:54:04PM +0100, Chris Wilson wrote:
> Inside pread, we only ever read from the GTT so the serialising wmb()
> instructions around the GGTT PTE updates are pointless.
Hard to argue with that.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_gem.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index a207b90924e4..fed0bc421a55 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -395,11 +395,9 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj,
> unsigned page_length = PAGE_SIZE - page_offset;
> page_length = remain < page_length ? remain : page_length;
> if (node.allocated) {
> - wmb();
> ggtt->vm.insert_page(&ggtt->vm,
> i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT),
> node.start, I915_CACHE_NONE, 0);
> - wmb();
> } else {
> page_base += offset & PAGE_MASK;
> }
> @@ -419,7 +417,6 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj,
> out_unpin:
> mutex_lock(&i915->drm.struct_mutex);
> if (node.allocated) {
> - wmb();
> ggtt->vm.clear_range(&ggtt->vm, node.start, node.size);
> remove_mappable_node(&node);
> } else {
> --
> 2.22.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrjälä
Intel
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prev parent reply other threads:[~2019-07-18 18:23 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-18 14:54 [PATCH 1/4] drm/i915: Drop wmb() inside pread_gtt Chris Wilson
2019-07-18 14:54 ` [PATCH 2/4] drm/i915: Use maximum write flush for pwrite_gtt Chris Wilson
2019-07-18 18:28 ` Ville Syrjälä
2019-07-18 19:19 ` Chris Wilson
2019-07-19 0:45 ` Sasha Levin
2019-07-18 14:54 ` [PATCH 3/4] drm/i915: Flush all user surfaces prior to first use Chris Wilson
2019-07-19 10:01 ` Joonas Lahtinen
2019-07-19 10:18 ` Lionel Landwerlin
2019-07-19 10:21 ` Chris Wilson
2019-07-19 22:55 ` Jason Ekstrand
2019-07-20 10:49 ` Chris Wilson
2019-07-24 20:37 ` Francisco Jerez
2019-11-12 9:38 ` Chris Wilson
2019-11-12 9:38 ` [Intel-gfx] " Chris Wilson
2019-11-12 19:58 ` Francisco Jerez
2019-11-12 19:58 ` [Intel-gfx] " Francisco Jerez
2019-07-18 14:54 ` [PATCH 4/4] drm/i915: Flush stale cachelines on set-cache-level Chris Wilson
2019-07-19 10:03 ` Joonas Lahtinen
2019-11-12 9:09 ` [Intel-gfx] " Daniel Vetter
2019-11-12 9:09 ` Daniel Vetter
2019-11-12 9:42 ` Chris Wilson
2019-11-12 9:42 ` Chris Wilson
2019-11-12 10:57 ` Daniel Vetter
2019-11-12 10:57 ` Daniel Vetter
2019-11-12 12:08 ` Daniel Vetter
2019-11-12 12:08 ` Daniel Vetter
2019-07-18 15:35 ` ✗ Fi.CI.CHECKPATCH: warning for series starting with [1/4] drm/i915: Drop wmb() inside pread_gtt Patchwork
2019-07-18 16:22 ` ✓ Fi.CI.BAT: success " Patchwork
2019-07-18 17:29 ` ✓ Fi.CI.IGT: " Patchwork
2019-07-18 18:23 ` Ville Syrjälä [this message]
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