| Message ID | 20180516054348.15950-11-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 16, 2018 at 07:43:44AM +0200, Christoph Hellwig wrote: > And streamline the code in vgem_fault with early returns so that it is > a little bit more readable. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/gpu/drm/vgem/vgem_drv.c | 51 +++++++++++++++------------------ > 1 file changed, 23 insertions(+), 28 deletions(-) > > diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c > index 2524ff116f00..a261e0aab83a 100644 > --- a/drivers/gpu/drm/vgem/vgem_drv.c > +++ b/drivers/gpu/drm/vgem/vgem_drv.c > @@ -61,12 +61,13 @@ static void vgem_gem_free_object(struct drm_gem_object *obj) > kfree(vgem_obj); > } > > -static int vgem_gem_fault(struct vm_fault *vmf) > +static vm_fault_t vgem_gem_fault(struct vm_fault *vmf) > { > struct vm_area_struct *vma = vmf->vma; > struct drm_vgem_gem_object *obj = vma->vm_private_data; > /* We don't use vmf->pgoff since that has the fake offset */ > unsigned long vaddr = vmf->address; > + struct page *page; > int ret; > loff_t num_pages; > pgoff_t page_offset; > @@ -85,35 +86,29 @@ static int vgem_gem_fault(struct vm_fault *vmf) > ret = 0; > } > mutex_unlock(&obj->pages_lock); > - if (ret) { > - struct page *page; > - > - page = shmem_read_mapping_page( > - file_inode(obj->base.filp)->i_mapping, > - page_offset); > - if (!IS_ERR(page)) { > - vmf->page = page; > - ret = 0; > - } else switch (PTR_ERR(page)) { > - case -ENOSPC: > - case -ENOMEM: > - ret = VM_FAULT_OOM; > - break; > - case -EBUSY: > - ret = VM_FAULT_RETRY; > - break; > - case -EFAULT: > - case -EINVAL: > - ret = VM_FAULT_SIGBUS; > - break; > - default: > - WARN_ON(PTR_ERR(page)); > - ret = VM_FAULT_SIGBUS; > - break; > - } > + if (!ret) > + return 0; > + > + page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping, > + page_offset); > + if (!IS_ERR(page)) { > + vmf->page = page; > + return 0; > + } > > + switch (PTR_ERR(page)) { > + case -ENOSPC: > + case -ENOMEM: > + return VM_FAULT_OOM; > + case -EBUSY: > + return VM_FAULT_RETRY; > + case -EFAULT: > + case -EINVAL: > + return VM_FAULT_SIGBUS; > + default: > + WARN_ON(PTR_ERR(page)); > + return VM_FAULT_SIGBUS; > } > - return ret; Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Want me to merge this through drm-misc or plan to pick it up yourself? -Daniel > } > > static const struct vm_operations_struct vgem_gem_vm_ops = { > -- > 2.17.0 >
On Wed, May 16, 2018 at 11:53:03AM +0200, Daniel Vetter wrote: > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > Want me to merge this through drm-misc or plan to pick it up yourself? For now I just want a honest discussion if people really actually want the vm_fault_t change with the whole picture in place.
On Wed, May 16, 2018 at 03:01:59PM +0200, Christoph Hellwig wrote: > On Wed, May 16, 2018 at 11:53:03AM +0200, Daniel Vetter wrote: > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > > > Want me to merge this through drm-misc or plan to pick it up yourself? > > For now I just want a honest discussion if people really actually > want the vm_fault_t change with the whole picture in place. That discussion already happened on the -mm mailing list. And again at LSFMM. Both times the answer was yes.
diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c index 2524ff116f00..a261e0aab83a 100644 --- a/drivers/gpu/drm/vgem/vgem_drv.c +++ b/drivers/gpu/drm/vgem/vgem_drv.c @@ -61,12 +61,13 @@ static void vgem_gem_free_object(struct drm_gem_object *obj) kfree(vgem_obj); } -static int vgem_gem_fault(struct vm_fault *vmf) +static vm_fault_t vgem_gem_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_vgem_gem_object *obj = vma->vm_private_data; /* We don't use vmf->pgoff since that has the fake offset */ unsigned long vaddr = vmf->address; + struct page *page; int ret; loff_t num_pages; pgoff_t page_offset; @@ -85,35 +86,29 @@ static int vgem_gem_fault(struct vm_fault *vmf) ret = 0; } mutex_unlock(&obj->pages_lock); - if (ret) { - struct page *page; - - page = shmem_read_mapping_page( - file_inode(obj->base.filp)->i_mapping, - page_offset); - if (!IS_ERR(page)) { - vmf->page = page; - ret = 0; - } else switch (PTR_ERR(page)) { - case -ENOSPC: - case -ENOMEM: - ret = VM_FAULT_OOM; - break; - case -EBUSY: - ret = VM_FAULT_RETRY; - break; - case -EFAULT: - case -EINVAL: - ret = VM_FAULT_SIGBUS; - break; - default: - WARN_ON(PTR_ERR(page)); - ret = VM_FAULT_SIGBUS; - break; - } + if (!ret) + return 0; + + page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping, + page_offset); + if (!IS_ERR(page)) { + vmf->page = page; + return 0; + } + switch (PTR_ERR(page)) { + case -ENOSPC: + case -ENOMEM: + return VM_FAULT_OOM; + case -EBUSY: + return VM_FAULT_RETRY; + case -EFAULT: + case -EINVAL: + return VM_FAULT_SIGBUS; + default: + WARN_ON(PTR_ERR(page)); + return VM_FAULT_SIGBUS; } - return ret; } static const struct vm_operations_struct vgem_gem_vm_ops = {
And streamline the code in vgem_fault with early returns so that it is a little bit more readable. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/gpu/drm/vgem/vgem_drv.c | 51 +++++++++++++++------------------ 1 file changed, 23 insertions(+), 28 deletions(-)