| Message ID | 20191011173823.20432-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Add an rcu_barrier option to i915_drop_caches | expand |
On Fri, 11 Oct 2019 at 18:38, Chris Wilson <chris@chris-wilson.co.uk> wrote: > > Sometimes a test has to wait for RCU to complete a grace period and > perform its callbacks, for example waiting for a close(fd) to actually > perform the fput(filp) and so trigger all the callbacks such as closing > GEM contexts. There is no trivial means of triggering an RCU barrier > from userspace, so add one for our convenience in > debugfs/i915_drop_caches > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Matthew Auld <matthew.william.auld@gmail.com> Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 29c918a1580e..c7fc402bd8f3 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -3513,6 +3513,7 @@ DEFINE_SIMPLE_ATTRIBUTE(i915_wedged_fops, #define DROP_IDLE BIT(6) #define DROP_RESET_ACTIVE BIT(7) #define DROP_RESET_SEQNO BIT(8) +#define DROP_RCU BIT(9) #define DROP_ALL (DROP_UNBOUND | \ DROP_BOUND | \ DROP_RETIRE | \ @@ -3521,7 +3522,8 @@ DEFINE_SIMPLE_ATTRIBUTE(i915_wedged_fops, DROP_SHRINK_ALL |\ DROP_IDLE | \ DROP_RESET_ACTIVE | \ - DROP_RESET_SEQNO) + DROP_RESET_SEQNO | \ + DROP_RCU) static int i915_drop_caches_get(void *data, u64 *val) { @@ -3573,6 +3575,9 @@ i915_drop_caches_set(void *data, u64 val) i915_gem_shrink_all(i915); fs_reclaim_release(GFP_KERNEL); + if (val & DROP_RCU) + rcu_barrier(); + if (val & DROP_FREED) i915_gem_drain_freed_objects(i915);
Sometimes a test has to wait for RCU to complete a grace period and perform its callbacks, for example waiting for a close(fd) to actually perform the fput(filp) and so trigger all the callbacks such as closing GEM contexts. There is no trivial means of triggering an RCU barrier from userspace, so add one for our convenience in debugfs/i915_drop_caches Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.william.auld@gmail.com> --- drivers/gpu/drm/i915/i915_debugfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)