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 3887736D4E5; Mon, 1 Dec 2025 08:46:02 +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=1764578765; cv=none; b=B8o7ZwEJOumss8EkwGn2jI8eGQIwRWHOSLMBmA2nM2Lyw+GLZt6r7HQFYmDcZFxku78xkD9U50HJ6YUu/2TSKne1Q/+UJGKlhbSCoUjmUIeKCsNnWMVbM2ARnYSJOp+4Sneqbrfh3upmxAPESJZMxW+k5YJAjwWWWLxQf+SfZG8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764578765; c=relaxed/simple; bh=OAnS/yXE9nV5UZXIRrvCT7YzkHlT6SyTgUSWEbYw4YU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tzedXUxBX+zaLjM7Iz+MtsA7N7FN1wp9i2RgCCEgZ8bEMgUpknjImUOPdGbuEm67GBchj5RquQeSXUiVyneK7uHKEv8yuhoSTyRBNL/94aQfzdm+FLq/9yXgosvlJqq3xgBNs4GPP5/as74Ea7wMq3f5byO2SUouZ1DoNS70gf4= 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=QRQ92yMr; 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="QRQ92yMr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1764578761; bh=OAnS/yXE9nV5UZXIRrvCT7YzkHlT6SyTgUSWEbYw4YU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QRQ92yMr4FxswuS7dMmtS0/G7FNb+cGDfYbWV/1BTYAstPkV1ut/wZRMAMI6QmvPy QeYmqgYEafyKz/1PDHi5w6Rc+hGNF5UfldfSz6m37VlnlAYYxoqA8/a0d3N3xdB4fW cf8Jy0yFMyab4zkWe6d1PIlbbj3Ss5w6YSobXHPq/Z/6qjpkTzMb1bdPLzYDD3Egwt wiDI69uCGF9/PLyv4LWZRJJkkEQA9DVzdmxmRVhHrmOimQnE57ZtQ52tXcI7sf2oPA c2241tHA+vHP/1bv+qagLzq0vZev5wOBExyTLjV3zpPwO7cnd4dn0Cg+Dl/QjjM20b YlbNdkfLEOtmg== 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 41EAA17E013C; Mon, 1 Dec 2025 09:46:00 +0100 (CET) Date: Mon, 1 Dec 2025 09:45:55 +0100 From: Boris Brezillon To: =?UTF-8?B?TG/Dr2M=?= Molinari Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , Rob Herring , Steven Price , Liviu Dudau , Melissa Wen , =?UTF-8?B?TWHDrXJh?= Canal , Hugh Dickins , Baolin Wang , Andrew Morton , Al Viro , =?UTF-8?B?TWlrb8WCYWo=?= Wasiak , Christian Brauner , Nitin Gote , Andi Shyti , Jonathan Corbet , Christopher Healy , Matthew Wilcox , Bagas Sanjaya , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCH v10 08/10] drm/panthor: Introduce huge tmpfs mountpoint option Message-ID: <20251201094555.595744ab@fedora> In-Reply-To: <20251128185252.3092-9-loic.molinari@collabora.com> References: <20251128185252.3092-1-loic.molinari@collabora.com> <20251128185252.3092-9-loic.molinari@collabora.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-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, 28 Nov 2025 19:52:50 +0100 Lo=C3=AFc Molinari wrote: > Introduce the 'panthor.transparent_hugepage' boolean module parameter > (false by default). When the parameter is set to true, a new tmpfs > mountpoint is created and mounted using the 'huge=3Dwithin_size' > option. It's then used at GEM object creation instead of the default > 'shm_mnt' mountpoint in order to enable Transparent Hugepage (THP) for > the object (without having to rely on a system wide parameter). >=20 > v3: > - use huge tmpfs mountpoint in drm_device >=20 > v4: > - fix builds with CONFIG_TRANSPARENT_HUGEPAGE=3Dn > - clean up mountpoint creation error handling > - print negative error value >=20 > v5: > - use drm_gem_has_huge_tmp() helper > - get rid of CONFIG_TRANSPARENT_HUGEPAGE ifdefs >=20 > v9: > - replace drm_gem_has_huge_tmp() by drm_gem_get_huge_tmp() >=20 > Signed-off-by: Lo=C3=AFc Molinari > Reviewed-by: Boris Brezillon > --- > drivers/gpu/drm/panthor/panthor_device.c | 3 +++ > drivers/gpu/drm/panthor/panthor_drv.c | 7 +++++++ > drivers/gpu/drm/panthor/panthor_drv.h | 9 +++++++++ > drivers/gpu/drm/panthor/panthor_gem.c | 18 ++++++++++++++++++ > drivers/gpu/drm/panthor/panthor_gem.h | 2 ++ > 5 files changed, 39 insertions(+) > create mode 100644 drivers/gpu/drm/panthor/panthor_drv.h >=20 > diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/p= anthor/panthor_device.c > index e133b1e0ad6d..2979ee0e52c2 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.c > +++ b/drivers/gpu/drm/panthor/panthor_device.c > @@ -18,6 +18,7 @@ > #include "panthor_devfreq.h" > #include "panthor_device.h" > #include "panthor_fw.h" > +#include "panthor_gem.h" > #include "panthor_gpu.h" > #include "panthor_hw.h" > #include "panthor_mmu.h" > @@ -294,6 +295,8 @@ int panthor_device_init(struct panthor_device *ptdev) > if (ret) > goto err_unplug_fw; > =20 > + panthor_gem_init(ptdev); > + > /* ~3 frames */ > pm_runtime_set_autosuspend_delay(ptdev->base.dev, 50); > pm_runtime_use_autosuspend(ptdev->base.dev); > diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/pant= hor/panthor_drv.c > index d1d4c50da5bf..55dbda6dbf9c 100644 > --- a/drivers/gpu/drm/panthor/panthor_drv.c > +++ b/drivers/gpu/drm/panthor/panthor_drv.c > @@ -1559,6 +1559,7 @@ static const struct file_operations panthor_drm_dri= ver_fops =3D { > .read =3D drm_read, > .llseek =3D noop_llseek, > .mmap =3D panthor_mmap, > + .get_unmapped_area =3D drm_gem_get_unmapped_area, > .show_fdinfo =3D drm_show_fdinfo, > .fop_flags =3D FOP_UNSIGNED_OFFSET, > }; > @@ -1626,6 +1627,12 @@ static const struct drm_driver panthor_drm_driver = =3D { > #endif > }; > =20 > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +bool panthor_transparent_hugepage; > +module_param_named(transparent_hugepage, panthor_transparent_hugepage, b= ool, 0400); > +MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount poin= t with Transparent Hugepage enabled (false =3D default)"); On a second thought, I wonder if this shouldn't be an opt-out param (which is what V3D does, BTW). What's the downside of enabling THP if we have a fallback for cases where memory is too fragmented to get huge pages at allocation time? > +#endif > + > static int panthor_probe(struct platform_device *pdev) > { > struct panthor_device *ptdev; > diff --git a/drivers/gpu/drm/panthor/panthor_drv.h b/drivers/gpu/drm/pant= hor/panthor_drv.h > new file mode 100644 > index 000000000000..79dccd289881 > --- /dev/null > +++ b/drivers/gpu/drm/panthor/panthor_drv.h > @@ -0,0 +1,9 @@ > +// SPDX-License-Identifier: GPL-2.0 or MIT > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > + > +#ifndef __PANTHOR_DRV_H__ > +#define __PANTHOR_DRV_H__ > + > +extern bool panthor_transparent_hugepage; > + > +#endif > diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/pant= hor/panthor_gem.c > index 10d255cccc09..7ae07a9bc996 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.c > +++ b/drivers/gpu/drm/panthor/panthor_gem.c > @@ -1,6 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0 or MIT > /* Copyright 2019 Linaro, Ltd, Rob Herring */ > /* Copyright 2023 Collabora ltd. */ > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > =20 > #include > #include > @@ -12,10 +13,27 @@ > #include > =20 > #include "panthor_device.h" > +#include "panthor_drv.h" > #include "panthor_fw.h" > #include "panthor_gem.h" > #include "panthor_mmu.h" > =20 > +void panthor_gem_init(struct panthor_device *ptdev) > +{ > + int err; > + > + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && > + !panthor_transparent_hugepage) > + return; > + > + err =3D drm_gem_huge_mnt_create(&ptdev->base, "within_size"); > + if (drm_gem_get_huge_mnt(&ptdev->base)) > + drm_info(&ptdev->base, "Using Transparent Hugepage\n"); > + else if (err) > + drm_warn(&ptdev->base, "Can't use Transparent Hugepage (%d)\n", > + err); > +} > + > #ifdef CONFIG_DEBUG_FS > static void panthor_gem_debugfs_bo_init(struct panthor_gem_object *bo) > { > diff --git a/drivers/gpu/drm/panthor/panthor_gem.h b/drivers/gpu/drm/pant= hor/panthor_gem.h > index 80c6e24112d0..2eefe9104e5e 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.h > +++ b/drivers/gpu/drm/panthor/panthor_gem.h > @@ -136,6 +136,8 @@ struct panthor_gem_object *to_panthor_bo(struct drm_g= em_object *obj) > return container_of(to_drm_gem_shmem_obj(obj), struct panthor_gem_objec= t, base); > } > =20 > +void panthor_gem_init(struct panthor_device *ptdev); > + > struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev= , size_t size); > =20 > int