@@ -479,6 +479,7 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
pinned += ret;
}
+ __i915_gem_userptr_set_active(obj, true);
if (locked)
mmap_read_unlock(mm);
mmput(mm);
@@ -559,7 +560,6 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
struct mm_struct *mm = obj->userptr.mm->mm;
struct page **pvec;
struct sg_table *pages;
- bool active;
int pinned;
unsigned int gup_flags = 0;
@@ -614,19 +614,16 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
}
}
- active = false;
if (pinned < 0) {
pages = ERR_PTR(pinned);
pinned = 0;
} else if (pinned < num_pages) {
pages = __i915_gem_userptr_get_pages_schedule(obj);
- active = pages == ERR_PTR(-EAGAIN);
} else {
pages = __i915_gem_userptr_alloc_pages(obj, pvec, num_pages);
- active = !IS_ERR(pages);
+ if (!IS_ERR(pages))
+ __i915_gem_userptr_set_active(obj, true);
}
- if (active)
- __i915_gem_userptr_set_active(obj, true);
if (IS_ERR(pages))
unpin_user_pages(pvec, pinned);
On the fast path, we first try to pin the user pages and then attach the mmu-notifier. On the slow path, we did it the opposite way around, carrying the mmu-notifier over from the tail of the fast path. However, if we are mapping a fresh batch of user pages, we will always hit a pmd split operation (to replace the zero pages with real pages), triggering a invalidate-range callback for this userptr, and so we have to cancel the work [after completing the pinning] and cause the caller to retry (an extra EAGAIN return from an ioctl for some paths). If we follow the fast path and attach the callback after completion, we only see the invalidate-range for revocations of our pages. The risk (the same as for the fast path) is that if the mmu-notifier should have been run during the page lookup, we will have missed it and the pages will be mixed. One might conclude that the fast path is wrong, and we should always attach the mmu-notifier first and bear the cost of redundant repetition. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)