From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D89F5271476 for ; Wed, 26 Nov 2025 09:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764150749; cv=none; b=pgG/PfcOX+n4h4LhcE1o7SChhV17xh3xHndX2b/6WegWg4f+h7J/dZbnj20skWJFxkIYsxC6MDwD5rjqR7tDYE+iBf01Sygj4ZSqcNcCNzzN6qI8VkfVO78K2Z/2IlQEY67D1YVPDPxE843vCgnpOoEMcDgvj570iMZ+U2jReOE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764150749; c=relaxed/simple; bh=p2d6tWiC7zJzhOcMVqKqokGiR5sva9dnTCaqBmrZg6k=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=D+tsrInDPk3IcS49l5/k1erPAQBivlffhhvLYAdbz+CN1RQeoZrp+1Eep7R4GcXwsy3Gb0lQPN2JMIVxMx0tbB7dE+Pm/Nx7+nJ2RAlklo8bzcYb1p1HwNjEB6BNCE5ECFN1lPX3D9Yb5M+gJLU/qybb/NRdBjMlLNCkaOqmaws= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=guzeQBhY; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="guzeQBhY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1764150744; bh=p2d6tWiC7zJzhOcMVqKqokGiR5sva9dnTCaqBmrZg6k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=guzeQBhYYJS6oLt8RemQSyjvUDmqWMMxZVveDxXXqA2oX2ywGomIoTcG4+7kNvvCO TqV8TWYVXNPbyqHLmydv+A52hlan6YIk2Xd8FEg5dBTXkX/BafdSv+wreb/80Vg38z ZFF2Z3ZIPCPiejulD0apQ39ierN4+vyOJOXnSS/6KYCKoblvTPfwfvlhGx0EHCpI4n VUXgmPYVJNVEihuxKi2f20wEYvCIpcE2JK7aXD4dh8e1ta3Ep/v1xakvketfi5jAGa PMTqTQ0dqZRBX55SlFOTNA0WCtUVBy/+ozktek0RIezCsUnslQJbd//cdEHjuQV1Jy zMeyRXJmufxzg== Received: from fedora (unknown [IPv6:2a01:e0a:2c:6930:d919:a6e:5ea1:8a9f]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 72B1117E04D6; Wed, 26 Nov 2025 10:52:24 +0100 (CET) Date: Wed, 26 Nov 2025 10:52:19 +0100 From: Boris Brezillon To: Akash Goel Cc: liviu.dudau@arm.com, steven.price@arm.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, nd@arm.com Subject: Re: [PATCH v2] drm/panthor: Avoid adding of kernel BOs to extobj list Message-ID: <20251126105219.3a51430c@fedora> In-Reply-To: <20251120172118.2741724-1-akash.goel@arm.com> References: <20251120172118.2741724-1-akash.goel@arm.com> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 20 Nov 2025 17:21:18 +0000 Akash Goel wrote: > The kernel BOs unnecessarily got added to the external objects list > of drm_gpuvm, when mapping to GPU, which would have resulted in few > extra CPU cycles being spent at the time of job submission as > drm_exec_until_all_locked() loop iterates over all external objects. > > Kernel BOs are private to a VM and so they share the dma_resv object of > the dummy GEM object created for a VM. Use of DRM_EXEC_IGNORE_DUPLICATES > flag ensured the recursive locking of the dummy GEM object was ignored. > Also no extra space got allocated to add fences to the dma_resv object > of dummy GEM object. So no other impact apart from few extra CPU cycles. > > This commit sets the pointer to dma_resv object of GEM object of > kernel BOs before they are mapped to GPU, to prevent them from > being added to external objects list. > > v2: Add R-bs and fixes tags > > Fixes: 8a1cc07578bf ("drm/panthor: Add GEM logical block") > Signed-off-by: Akash Goel > Reviewed-by: Boris Brezillon > Reviewed-by: Steven Price Queued to drm-misc-next. > --- > drivers/gpu/drm/panthor/panthor_gem.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c > index f369cc3e2a5f..10d255cccc09 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.c > +++ b/drivers/gpu/drm/panthor/panthor_gem.c > @@ -145,6 +145,9 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm, > bo = to_panthor_bo(&obj->base); > kbo->obj = &obj->base; > bo->flags = bo_flags; > + bo->exclusive_vm_root_gem = panthor_vm_root_gem(vm); > + drm_gem_object_get(bo->exclusive_vm_root_gem); > + bo->base.base.resv = bo->exclusive_vm_root_gem->resv; > > if (vm == panthor_fw_vm(ptdev)) > debug_flags |= PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED; > @@ -168,9 +171,6 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm, > goto err_free_va; > > kbo->vm = panthor_vm_get(vm); > - bo->exclusive_vm_root_gem = panthor_vm_root_gem(vm); > - drm_gem_object_get(bo->exclusive_vm_root_gem); > - bo->base.base.resv = bo->exclusive_vm_root_gem->resv; > return kbo; > > err_free_va: