Module Name:    src
Committed By:   riastradh
Date:           Sun Dec 19 12:09:09 UTC 2021

Modified Files:
        src/sys/external/bsd/drm2/dist/drm/i915: i915_request.c

Log Message:
i915: Kludge: wait for RCU grace period in __i915_request_dtor.

Unfortunately, pool_cache_put does not guarantee that an RCU or
pserialize grace period has completed before it invokes the pool
cache's destructor.  This is likely to kill performance...


To generate a diff of this commit:
cvs rdiff -u -r1.10 -r1.11 \
    src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c
diff -u src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c:1.10 src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c:1.11
--- src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c:1.10	Sun Dec 19 12:03:48 2021
+++ src/sys/external/bsd/drm2/dist/drm/i915/i915_request.c	Sun Dec 19 12:09:09 2021
@@ -1,4 +1,4 @@
-/*	$NetBSD: i915_request.c,v 1.10 2021/12/19 12:03:48 riastradh Exp $	*/
+/*	$NetBSD: i915_request.c,v 1.11 2021/12/19 12:09:09 riastradh Exp $	*/
 
 /*
  * Copyright © 2008-2015 Intel Corporation
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i915_request.c,v 1.10 2021/12/19 12:03:48 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i915_request.c,v 1.11 2021/12/19 12:09:09 riastradh Exp $");
 
 #include <linux/dma-fence-array.h>
 #include <linux/irq_work.h>
@@ -614,6 +614,11 @@ static void __i915_request_dtor(void *ar
 {
 	struct i915_request *rq = arg;
 
+#ifdef __NetBSD__
+	/* XXX pool cache does not guarantee this for us.  */
+	synchronize_rcu();
+#endif
+
 	dma_fence_destroy(&rq->fence);
 #ifdef __NetBSD__
 	i915_sw_fence_fini(&rq->submit);

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