summaryrefslogtreecommitdiff
path: root/include/drm/drm_file.h
diff options
context:
space:
mode:
authorChris Wilson <chris@chris-wilson.co.uk>2020-01-24 15:56:26 +0300
committerChris Wilson <chris@chris-wilson.co.uk>2020-01-24 20:41:34 +0300
commit7a2c65dd32b1cfa8bae55250dfdfe3d049e2f336 (patch)
tree0e99dbcc57f63cf27809945e3efd0d12af08112f /include/drm/drm_file.h
parentc2d4290ba0fff0aad5bc491af18adfbc88bf1c8c (diff)
downloadlinux-7a2c65dd32b1cfa8bae55250dfdfe3d049e2f336.tar.xz
drm: Release filp before global lock
The file is not part of the global drm resource and can be released prior to take the global mutex to drop the open_count (and potentially close) the drm device. As the global mutex is indeed global, not only within the device but across devices, a slow file release mechanism can bottleneck the entire system. However, inside drm_close_helper() there are a number of dev->driver callbacks that take the drm_device as the first parameter... Worryingly some of those callbacks may be (implicitly) depending on the global mutex. v2: Drop the debug message for the open-count, it's included with the drm_file_free() debug message -- and for good measure make that up as reading outside of the mutex. v3: Separate the calling of the filp cleanup outside of drm_global_mutex into a new drm_release_noglobal() hook, so that we can phase the transition. drm/savage relies on the global mutex, and there may be more, so be cautious. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Thomas Hellström (VMware) <thomas_os@shipmail.org> Reviewed-by: Thomas Hellström (VMware) <thomas_os@shipmail.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200124125627.125042-1-chris@chris-wilson.co.uk
Diffstat (limited to 'include/drm/drm_file.h')
-rw-r--r--include/drm/drm_file.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 8b099b347817..19df8028a6c4 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -374,6 +374,7 @@ int drm_open(struct inode *inode, struct file *filp);
ssize_t drm_read(struct file *filp, char __user *buffer,
size_t count, loff_t *offset);
int drm_release(struct inode *inode, struct file *filp);
+int drm_release_noglobal(struct inode *inode, struct file *filp);
__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait);
int drm_event_reserve_init_locked(struct drm_device *dev,
struct drm_file *file_priv,