[PATCH] drm: Eliminate dev->vmalist
David Herrmann
dh.herrmann at gmail.com
Sat Aug 17 05:46:41 PDT 2013
Hi
On Fri, Aug 16, 2013 at 1:24 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> The primary purpose of this list is for pretty printing the maps through
> debugfs/vma - per process information can be found in /proc/*/map et al.
> However, the list manipulation eats processor cycles resulting in a near
> indefinite (I got bored) stall for a leaky i-g-t/gem_concurrent_blit.
>
> There is one true user of the vmalist though. drm_vm_shm_close() uses
> the list to count the number of drm_local_map references. For this, we
> switch to using a counter inside drm_local_map.
>
> This patch kills drm_vm_open_locked and drm_vm_close_locked, and
> redirects the one user outside of the core (exoynos) to use the now
> semantically equivalent drm_gem_vm_open.
I don't like the drm_vma_open/close() function names. We currently use
the "drm_vma_*" prefix in drm_vma_manager.c. On the other hand, this
file exclusively uses "drm_vma_node_*" and "drm_vma_offset_*"
prefixes, so maybe we're fine here. Don't know..
I tried removing drm_vma_open/close entirely, but it seems not all
drivers set vma->vma_file->private_data to the drm_device, hmm. So the
patch looks fine:
Reviewed-by: David Herrmann <dh.herrmann at gmail.com>
Regards
David
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: Rob Clark <robdclark at gmail.com>
> Cc: Inki Dae <inki.dae at samsung.com>
> ---
> drivers/gpu/drm/drm_bufs.c | 1 +
> drivers/gpu/drm/drm_drv.c | 8 -----
> drivers/gpu/drm/drm_gem.c | 16 +++------
> drivers/gpu/drm/drm_info.c | 38 ---------------------
> drivers/gpu/drm/drm_stub.c | 1 -
> drivers/gpu/drm/drm_vm.c | 58 +++++++--------------------------
> drivers/gpu/drm/exynos/exynos_drm_gem.c | 9 +----
> include/drm/drmP.h | 7 ++--
> 8 files changed, 20 insertions(+), 118 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
> index bef4abf..b0aa2eb 100644
> --- a/drivers/gpu/drm/drm_bufs.c
> +++ b/drivers/gpu/drm/drm_bufs.c
> @@ -152,6 +152,7 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
> map->size = size;
> map->flags = flags;
> map->type = type;
> + map->count = 0;
>
> /* Only allow shared memory to be removable since we only keep enough
> * book keeping information about shared memory to allow for removal
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index dddd799..7ec9959 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -182,8 +182,6 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
> */
> int drm_lastclose(struct drm_device * dev)
> {
> - struct drm_vma_entry *vma, *vma_temp;
> -
> DRM_DEBUG("\n");
>
> if (dev->driver->lastclose)
> @@ -203,12 +201,6 @@ int drm_lastclose(struct drm_device * dev)
> dev->sg = NULL;
> }
>
> - /* Clear vma list (only built for debugging) */
> - list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
> - list_del(&vma->head);
> - kfree(vma);
> - }
> -
> if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
> !drm_core_check_feature(dev, DRIVER_MODESET))
> drm_dma_takedown(dev);
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 9ab038c..84a5834 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -573,22 +573,16 @@ void drm_gem_vm_open(struct vm_area_struct *vma)
> struct drm_gem_object *obj = vma->vm_private_data;
>
> drm_gem_object_reference(obj);
> -
> - mutex_lock(&obj->dev->struct_mutex);
> - drm_vm_open_locked(obj->dev, vma);
> - mutex_unlock(&obj->dev->struct_mutex);
> + drm_vma_open(obj->dev, vma);
> }
> EXPORT_SYMBOL(drm_gem_vm_open);
>
> void drm_gem_vm_close(struct vm_area_struct *vma)
> {
> struct drm_gem_object *obj = vma->vm_private_data;
> - struct drm_device *dev = obj->dev;
>
> - mutex_lock(&dev->struct_mutex);
> - drm_vm_close_locked(obj->dev, vma);
> - drm_gem_object_unreference(obj);
> - mutex_unlock(&dev->struct_mutex);
> + drm_vma_close(obj->dev, vma);
> + drm_gem_object_unreference_unlocked(obj);
> }
> EXPORT_SYMBOL(drm_gem_vm_close);
>
> @@ -639,9 +633,7 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
> * (which should happen whether the vma was created by this call, or
> * by a vm_open due to mremap or partial unmap or whatever).
> */
> - drm_gem_object_reference(obj);
> -
> - drm_vm_open_locked(dev, vma);
> + drm_gem_vm_open(vma);
> return 0;
> }
> EXPORT_SYMBOL(drm_gem_mmap_obj);
> diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c
> index d4b20ce..6ea817c 100644
> --- a/drivers/gpu/drm/drm_info.c
> +++ b/drivers/gpu/drm/drm_info.c
> @@ -228,49 +228,11 @@ int drm_vma_info(struct seq_file *m, void *data)
> {
> struct drm_info_node *node = (struct drm_info_node *) m->private;
> struct drm_device *dev = node->minor->dev;
> - struct drm_vma_entry *pt;
> - struct vm_area_struct *vma;
> -#if defined(__i386__)
> - unsigned int pgprot;
> -#endif
>
> - mutex_lock(&dev->struct_mutex);
> seq_printf(m, "vma use count: %d, high_memory = %pK, 0x%pK\n",
> atomic_read(&dev->vma_count),
> high_memory, (void *)(unsigned long)virt_to_phys(high_memory));
>
> - list_for_each_entry(pt, &dev->vmalist, head) {
> - vma = pt->vma;
> - if (!vma)
> - continue;
> - seq_printf(m,
> - "\n%5d 0x%pK-0x%pK %c%c%c%c%c%c 0x%08lx000",
> - pt->pid,
> - (void *)vma->vm_start, (void *)vma->vm_end,
> - vma->vm_flags & VM_READ ? 'r' : '-',
> - vma->vm_flags & VM_WRITE ? 'w' : '-',
> - vma->vm_flags & VM_EXEC ? 'x' : '-',
> - vma->vm_flags & VM_MAYSHARE ? 's' : 'p',
> - vma->vm_flags & VM_LOCKED ? 'l' : '-',
> - vma->vm_flags & VM_IO ? 'i' : '-',
> - vma->vm_pgoff);
> -
> -#if defined(__i386__)
> - pgprot = pgprot_val(vma->vm_page_prot);
> - seq_printf(m, " %c%c%c%c%c%c%c%c%c",
> - pgprot & _PAGE_PRESENT ? 'p' : '-',
> - pgprot & _PAGE_RW ? 'w' : 'r',
> - pgprot & _PAGE_USER ? 'u' : 's',
> - pgprot & _PAGE_PWT ? 't' : 'b',
> - pgprot & _PAGE_PCD ? 'u' : 'c',
> - pgprot & _PAGE_ACCESSED ? 'a' : '-',
> - pgprot & _PAGE_DIRTY ? 'd' : '-',
> - pgprot & _PAGE_PSE ? 'm' : 'k',
> - pgprot & _PAGE_GLOBAL ? 'g' : 'l');
> -#endif
> - seq_printf(m, "\n");
> - }
> - mutex_unlock(&dev->struct_mutex);
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
> index d663f7d..0a1db60 100644
> --- a/drivers/gpu/drm/drm_stub.c
> +++ b/drivers/gpu/drm/drm_stub.c
> @@ -258,7 +258,6 @@ int drm_fill_in_dev(struct drm_device *dev,
>
> INIT_LIST_HEAD(&dev->filelist);
> INIT_LIST_HEAD(&dev->ctxlist);
> - INIT_LIST_HEAD(&dev->vmalist);
> INIT_LIST_HEAD(&dev->maplist);
> INIT_LIST_HEAD(&dev->vblank_event_list);
>
> diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
> index feb2003..bc2b26f 100644
> --- a/drivers/gpu/drm/drm_vm.c
> +++ b/drivers/gpu/drm/drm_vm.c
> @@ -213,7 +213,6 @@ static void drm_vm_shm_close(struct vm_area_struct *vma)
> {
> struct drm_file *priv = vma->vm_file->private_data;
> struct drm_device *dev = priv->minor->dev;
> - struct drm_vma_entry *pt, *temp;
> struct drm_local_map *map;
> struct drm_map_list *r_list;
> int found_maps = 0;
> @@ -225,17 +224,8 @@ static void drm_vm_shm_close(struct vm_area_struct *vma)
> map = vma->vm_private_data;
>
> mutex_lock(&dev->struct_mutex);
> - list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
> - if (pt->vma->vm_private_data == map)
> - found_maps++;
> - if (pt->vma == vma) {
> - list_del(&pt->head);
> - kfree(pt);
> - }
> - }
> -
> /* We were the only map that was found */
> - if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
> + if (--map->count == 0) {
> /* Check to see if we are in the maplist, if we are not, then
> * we delete this mappings information.
> */
> @@ -402,68 +392,41 @@ static const struct vm_operations_struct drm_vm_sg_ops = {
> * Create a new drm_vma_entry structure as the \p vma private data entry and
> * add it to drm_device::vmalist.
> */
> -void drm_vm_open_locked(struct drm_device *dev,
> - struct vm_area_struct *vma)
> +void drm_vma_open(struct drm_device *dev,
> + struct vm_area_struct *vma)
> {
> - struct drm_vma_entry *vma_entry;
> -
> DRM_DEBUG("0x%08lx,0x%08lx\n",
> vma->vm_start, vma->vm_end - vma->vm_start);
> atomic_inc(&dev->vma_count);
> -
> - vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
> - if (vma_entry) {
> - vma_entry->vma = vma;
> - vma_entry->pid = current->pid;
> - list_add(&vma_entry->head, &dev->vmalist);
> - }
> }
> -EXPORT_SYMBOL_GPL(drm_vm_open_locked);
>
> static void drm_vm_open(struct vm_area_struct *vma)
> {
> struct drm_file *priv = vma->vm_file->private_data;
> struct drm_device *dev = priv->minor->dev;
>
> - mutex_lock(&dev->struct_mutex);
> - drm_vm_open_locked(dev, vma);
> - mutex_unlock(&dev->struct_mutex);
> + drm_vma_open(dev, vma);
> }
>
> -void drm_vm_close_locked(struct drm_device *dev,
> - struct vm_area_struct *vma)
> +void drm_vma_close(struct drm_device *dev,
> + struct vm_area_struct *vma)
> {
> - struct drm_vma_entry *pt, *temp;
> -
> DRM_DEBUG("0x%08lx,0x%08lx\n",
> vma->vm_start, vma->vm_end - vma->vm_start);
> atomic_dec(&dev->vma_count);
> -
> - list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
> - if (pt->vma == vma) {
> - list_del(&pt->head);
> - kfree(pt);
> - break;
> - }
> - }
> }
>
> /**
> * \c close method for all virtual memory types.
> *
> * \param vma virtual memory area.
> - *
> - * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
> - * free it.
> */
> static void drm_vm_close(struct vm_area_struct *vma)
> {
> struct drm_file *priv = vma->vm_file->private_data;
> struct drm_device *dev = priv->minor->dev;
>
> - mutex_lock(&dev->struct_mutex);
> - drm_vm_close_locked(dev, vma);
> - mutex_unlock(&dev->struct_mutex);
> + drm_vma_close(dev, vma);
> }
>
> /**
> @@ -513,7 +476,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
>
> vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
>
> - drm_vm_open_locked(dev, vma);
> + drm_vma_open(dev, vma);
> return 0;
> }
>
> @@ -543,7 +506,7 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
> {
> struct drm_file *priv = filp->private_data;
> struct drm_device *dev = priv->minor->dev;
> - struct drm_local_map *map = NULL;
> + struct drm_local_map *map;
> resource_size_t offset = 0;
> struct drm_hash_item *hash;
>
> @@ -648,8 +611,9 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
> return -EINVAL; /* This should never happen. */
> }
> vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
> + map->count++;
>
> - drm_vm_open_locked(dev, vma);
> + drm_vma_open(dev, vma);
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index b904633..04cb3ea 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -401,14 +401,7 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp,
> return ret;
> }
>
> - /*
> - * take a reference to this mapping of the object. And this reference
> - * is unreferenced by the corresponding vm_close call.
> - */
> - drm_gem_object_reference(obj);
> -
> - drm_vm_open_locked(drm_dev, vma);
> -
> + drm_gem_vm_open(vma);
> return 0;
> }
>
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 3ecdde6..e4b8658 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -573,6 +573,7 @@ struct drm_local_map {
> void *handle; /**< User-space: "Handle" to pass to mmap() */
> /**< Kernel-space: kernel-virtual address */
> int mtrr; /**< MTRR slot used */
> + int count;
> };
>
> typedef struct drm_local_map drm_local_map_t;
> @@ -1116,8 +1117,6 @@ struct drm_device {
>
> struct idr ctx_idr;
>
> - struct list_head vmalist; /**< List of vmas (for debugging) */
> -
> /*@} */
>
> /** \name DMA support */
> @@ -1274,8 +1273,8 @@ extern int drm_release(struct inode *inode, struct file *filp);
> /* Mapping support (drm_vm.h) */
> extern int drm_mmap(struct file *filp, struct vm_area_struct *vma);
> extern int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma);
> -extern void drm_vm_open_locked(struct drm_device *dev, struct vm_area_struct *vma);
> -extern void drm_vm_close_locked(struct drm_device *dev, struct vm_area_struct *vma);
> +extern void drm_vma_open(struct drm_device *dev, struct vm_area_struct *vma);
> +extern void drm_vma_close(struct drm_device *dev, struct vm_area_struct *vma);
> extern unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait);
>
> /* Memory management support (drm_memory.h) */
> --
> 1.8.4.rc2
>
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