diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-11-11 13:32:04 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-11-11 15:46:45 +0000 |
| commit | d323c9b88260bc2cf3e3ed4bc741ab69643e0233 (patch) | |
| tree | ffbb2dd4412b57556af3bd82d45ac9ec3b1a9d27 /drivers/gpu/drm/i915/gem/i915_gem_userptr.c | |
| parent | 0d4bbe3d407f79438dc4f87943db21f7134cfc65 (diff) | |
drm/i915/userptr: Handle unlocked gup retries
Enable gup to retry and fault the pages outside of the mmap_sem lock in
our worker. As we are inside our worker, outside of any critical path,
we can allow the mmap_sem lock to be dropped in order to service a page
fault; this in turn allows the mm to populate the page using a slow
fault handler.
References: 5b56d49fc31d ("mm: add locked parameter to get_user_pages_remote()")
Testcase: igt/gem_userptr/userfault
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191111133205.11590-2-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_userptr.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index dd104b0e2071..54ebc7ab71bc 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -459,26 +459,31 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work) if (pvec != NULL) { struct mm_struct *mm = obj->userptr.mm->mm; unsigned int flags = 0; + int locked = 0; if (!i915_gem_object_is_readonly(obj)) flags |= FOLL_WRITE; ret = -EFAULT; if (mmget_not_zero(mm)) { - down_read(&mm->mmap_sem); while (pinned < npages) { + if (!locked) { + down_read(&mm->mmap_sem); + locked = 1; + } ret = get_user_pages_remote (work->task, mm, obj->userptr.ptr + pinned * PAGE_SIZE, npages - pinned, flags, - pvec + pinned, NULL, NULL); + pvec + pinned, NULL, &locked); if (ret < 0) break; pinned += ret; } - up_read(&mm->mmap_sem); + if (locked) + up_read(&mm->mmap_sem); mmput(mm); } } |