On Sat, 4 Oct 2025 11:30:52 +0200 Loïc Molinari <[email protected]> wrote:
> Introduce the 'panfrost.transparent_hugepage' boolean module parameter > (false by default). When the parameter is set to true, a new tmpfs > mount point is created and mounted using the 'huge=within_size' > option. It's then used at GEM object creation instead of the default > 'shm_mnt' mount point in order to enable Transparent Hugepage (THP) > for the object (without having to rely on a system wide parameter). > > v3: > - use huge tmpfs mountpoint in drm_device > > Signed-off-by: Loïc Molinari <[email protected]> Reviewed-by: Boris Brezillon <[email protected]> A couple minor nits below. > --- > drivers/gpu/drm/panfrost/panfrost_device.c | 3 +++ > drivers/gpu/drm/panfrost/panfrost_drv.c | 6 ++++++ > drivers/gpu/drm/panfrost/panfrost_drv.h | 11 +++++++++++ > drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++ > drivers/gpu/drm/panfrost/panfrost_gem.h | 2 ++ > 5 files changed, 41 insertions(+) > create mode 100644 drivers/gpu/drm/panfrost/panfrost_drv.h > > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c > b/drivers/gpu/drm/panfrost/panfrost_device.c > index 04bec27449cb..a189bfaac959 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_device.c > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c > @@ -12,6 +12,7 @@ > #include "panfrost_device.h" > #include "panfrost_devfreq.h" > #include "panfrost_features.h" > +#include "panfrost_gem.h" > #include "panfrost_issues.h" > #include "panfrost_gpu.h" > #include "panfrost_job.h" > @@ -266,6 +267,8 @@ int panfrost_device_init(struct panfrost_device *pfdev) > if (err) > goto out_job; > > + panfrost_gem_init(pfdev); > + > return 0; > out_job: > panfrost_job_fini(pfdev); > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c > b/drivers/gpu/drm/panfrost/panfrost_drv.c > index 22350ce8a08f..e376e70a3379 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > @@ -862,6 +862,12 @@ static const struct drm_driver panfrost_drm_driver = { > #endif > }; > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +bool panfrost_transparent_hugepage; > +module_param_named(transparent_hugepage, panfrost_transparent_hugepage, > bool, 0400); > +MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount point > with Transparent Hugepage enabled (false = default)"); Same here, I'd go for [panfrost_]enable_thp. > +#endif > + > static int panfrost_probe(struct platform_device *pdev) > { > struct panfrost_device *pfdev; > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.h > b/drivers/gpu/drm/panfrost/panfrost_drv.h > new file mode 100644 > index 000000000000..60454611b6a6 > --- /dev/null > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.h > @@ -0,0 +1,11 @@ > +// SPDX-License-Identifier: GPL-2.0 or MIT > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > + > +#ifndef __PANFROST_DRV_H__ > +#define __PANFROST_DRV_H__ > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +extern bool panfrost_transparent_hugepage; > +#endif > + > +#endif > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c > b/drivers/gpu/drm/panfrost/panfrost_gem.c > index 85d6289a6eda..c3883a639e13 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c > @@ -1,5 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0 > /* Copyright 2019 Linaro, Ltd, Rob Herring <[email protected]> */ > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > > #include <linux/cleanup.h> > #include <linux/err.h> > @@ -9,9 +10,27 @@ > > #include <drm/panfrost_drm.h> > #include "panfrost_device.h" > +#include "panfrost_drv.h" > #include "panfrost_gem.h" > #include "panfrost_mmu.h" > > +void panfrost_gem_init(struct panfrost_device *pfdev) > +{ > + int err; > + > + if (!panfrost_transparent_hugepage) > + return; > + > + err = drm_gem_huge_mnt_create(pfdev->ddev, "within_size"); > + if (err && err != -EEXIST) { > + drm_warn(pfdev->ddev, "Can't use Transparent Hugepage (%d)\n", > + -err); I think errors are printed as negative values elsewhere, so I'd stick to err not -err here. > + return; > + } > + > + drm_info(pfdev->ddev, "Using Transparent Hugepage\n"); Here's a shorter version of the same thing (I dropped the EEXIST based on my comment on patch 3). if (err) drm_warn(pfdev->ddev, "Can't use Transparent Hugepage (err=%d)\n", err); else drm_info(pfdev->ddev, "Using Transparent Hugepage\n"); > +} > + > #ifdef CONFIG_DEBUG_FS > static void panfrost_gem_debugfs_bo_add(struct panfrost_device *pfdev, > struct panfrost_gem_object *bo) > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h > b/drivers/gpu/drm/panfrost/panfrost_gem.h > index 8de3e76f2717..1a62529ff06f 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_gem.h > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h > @@ -124,6 +124,8 @@ drm_mm_node_to_panfrost_mapping(struct drm_mm_node *node) > return container_of(node, struct panfrost_gem_mapping, mmnode); > } > > +void panfrost_gem_init(struct panfrost_device *pfdev); > + > struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, > size_t size); > > struct drm_gem_object *
