Now, i915_gem_inactive_shrink() should return -1 instead of 0 if it
can't take a lock. Otherwise, vmscan is getting a lot of confusing
because vmscan can't distinguish "can't take a lock temporary" and
"we've shrank all of i915 objects".
Signed-off-by: KOSAKI Motohiro <[email protected]>
Cc: Keith Packard <[email protected]>
Cc: David Airlie <[email protected]>
Cc: [email protected]
---
I've found this issue by reviewing. I hope i915 developers confirm this.
Thx.
drivers/gpu/drm/i915/i915_gem.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 94c84d7..2f9a9b2 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4104,7 +4104,7 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
int cnt;
if (!mutex_trylock(&dev->struct_mutex))
- return 0;
+ return nr_to_scan ? -1 : 0;
/* "fast-path" to count number of available objects */
if (nr_to_scan == 0) {
--
1.7.3.1
On Wed, 29 Jun 2011 20:53:54 -0700, Keith Packard <[email protected]> wrote:
> On Fri, 24 Jun 2011 17:03:22 +0900, KOSAKI Motohiro <[email protected]> wrote:
>
> > Now, i915_gem_inactive_shrink() should return -1 instead of 0 if it
> > can't take a lock. Otherwise, vmscan is getting a lot of confusing
> > because vmscan can't distinguish "can't take a lock temporary" and
> > "we've shrank all of i915 objects".
>
> This doesn't look like the cleanest change possible. I think it would be
> better if the shrink function could uniformly return an error
> indication so that we wouldn't need the weird looking conditional return.
Unless I am mistaken, and there are more patches in flight, the return
code from i915_gem_inactive_shrink() is promoted to unsigned long and then
used in the calculation of how may objects to evict...
-Chris
--
Chris Wilson, Intel Open Source Technology Centre