Re: [PATCH v3 05/10] drm/v3d: Use huge tmpfs mount point helper

[Boris Brezillon <boris.brezillon@collabora.com>]

On Sat,  4 Oct 2025 11:30:48 +0200
Loïc Molinari <loic.molinari@collabora.com> wrote:

> +static void
> +v3d_huge_mnt_init(struct v3d_dev *v3d)
> +{
> +	int err;
> +
> +	/*
> +	 * By creating our own shmemfs mountpoint, we can pass in
> +	 * mount flags that better match our usecase. However, we
> +	 * only do so on platforms which benefit from it.
> +	 */
> +	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
> +		goto err;
> +
> +	/* The user doesn't want to enable Super Pages */
> +	if (!super_pages)
> +		goto err;
> +
> +	err = drm_gem_huge_mnt_create(&v3d->drm, "within_size");
> +	if (err && err != -EEXIST)
> +		goto err;
> +
> +	drm_info(&v3d->drm, "Using Transparent Hugepages\n");
> +
> +	return;
> +
> +err:
> +	drm_notice(&v3d->drm,
> +		   "Transparent Hugepage support is recommended for optimal performance on this platform!\n");

With the changes suggested on patch 3, this can be shrunk a little bit:

	int err = 0;

	if (super_pages)
		err = drm_gem_huge_mnt_create(&v3d->drm, "within_size");

	if (v3d->drm.huge_mnt)
		drm_info(&v3d->drm, "Using Transparent Hugepages\n");
	else if (!err)
		drm_notice(&v3d->drm,
			   "Transparent Hugepage support is recommended for optimal performance on this platform!\n");
	else
		drm_warn(&v3d->drm, "Couldn't create THP mount point (err=%d)\n", err);