[PATCH v2 1/2] drm/msm: Enable THP for GEM buffers

[Rob Clark <robin.clark@oss.qualcomm.com>]

More than 2x speedup on darktable benchmark which was bottlenecked on
page allocation/pinning.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
v2: Initialize THP earlier
 drivers/gpu/drm/msm/msm_drv.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 73d99bde26f1..581903ccd5e6 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -58,9 +58,31 @@ static bool separate_gpu_kms;
 MODULE_PARM_DESC(separate_gpu_drm, "Use separate DRM device for the GPU (0=single DRM device for both GPU and display (default), 1=two DRM devices)");
 module_param(separate_gpu_kms, bool, 0400);
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static bool transparent_hugepage = true;
+module_param(transparent_hugepage, bool, 0400);
+MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount point with Transparent Hugepage enabled (true = default)");
+#else
+#define transparent_hugepage false
+#endif
+
 DECLARE_FAULT_ATTR(fail_gem_alloc);
 DECLARE_FAULT_ATTR(fail_gem_iova);
 
+static void msm_gem_thp_init(struct drm_device *dev)
+{
+	int err;
+
+	if (!transparent_hugepage)
+		return;
+
+	err = drm_gem_huge_mnt_create(dev, "within_size");
+	if (drm_gem_get_huge_mnt(dev))
+		drm_info(dev, "Using Transparent Hugepage\n");
+	else if (err)
+		drm_warn(dev, "Can't use Transparent Hugepage (%d)\n", err);
+}
+
 bool msm_gpu_no_components(void)
 {
 	return separate_gpu_kms;
@@ -161,6 +183,8 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv,
 	if (ret)
 		goto err_msm_uninit;
 
+	msm_gem_thp_init(ddev);
+
 	if (priv->kms_init) {
 		ret = msm_drm_kms_init(dev, drv);
 		if (ret)
-- 
2.55.0