Remove vars before TLS data during OpenACC shutdown
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Message ID 20191021141409.05209ab6@squid.athome
State New
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Series
  • Remove vars before TLS data during OpenACC shutdown
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Commit Message

Julian Brown Oct. 21, 2019, 1:14 p.m. UTC
This patch fixes a minor issue that could occur during OpenACC shutdown
on nvidia devices. The acc_shutdown_1 function freed TLS data before
unmapping variables, but the nvptx libgomp plugin uses the lack of TLS
data in nvptx_free as an indication that it is running from callback
context of the CUDA driver runtime, meaning it must add the block to a
list to be freed later (in nvptx_close_device).

With this patch, the data will be freed immediately instead. OK for
trunk?

Thanks,

Julian

ChangeLog

    libgomp/
    * oacc-init.c (acc_shutdown_1): Remove variable mappings
    before TLS data during OpenACC shutdown.

Patch
diff mbox series

commit bbf990a35ab5a7b5100b03c5c5aca11ef0729e7b
Author: Julian Brown <julian@codesourcery.com>
Date:   Fri Oct 18 11:47:37 2019 -0700

    Remove vars before TLS data during OpenACC shutdown
    
            libgomp/
            * oacc-init.c (acc_shutdown_1): Remove variable mappings before TLS
            data during OpenACC shutdown.

diff --git a/libgomp/oacc-init.c b/libgomp/oacc-init.c
index e0395ef43b2..ba51d09fa82 100644
--- a/libgomp/oacc-init.c
+++ b/libgomp/oacc-init.c
@@ -334,6 +334,20 @@  acc_shutdown_1 (acc_device_t d)
   /* Free target-specific TLS data and close all devices.  */
   for (walk = goacc_threads; walk != NULL; walk = walk->next)
     {
+      if (walk->dev)
+	{
+	  /* Free the splay tree before the TLS data below: the nvptx plugin
+	     uses the lack of TLS data as an indicator that device memory is
+	     being freed from (CUDA) callback context.  */
+	  while (walk->dev->mem_map.root)
+	    {
+	      splay_tree_key k = &walk->dev->mem_map.root->key;
+	      if (k->virtual_refcount == VREFCOUNT_LINK_KEY)
+		k->u.link_key = NULL;
+	      gomp_remove_var (walk->dev, k);
+	    }
+	}
+
       if (walk->target_tls)
 	base_dev->openacc.destroy_thread_data_func (walk->target_tls);
 
@@ -354,19 +368,8 @@  acc_shutdown_1 (acc_device_t d)
 	  gomp_fatal ("shutdown during host fallback");
 	}
 
-      if (walk->dev)
-	{
-	  while (walk->dev->mem_map.root)
-	    {
-	      splay_tree_key k = &walk->dev->mem_map.root->key;
-	      if (k->virtual_refcount == VREFCOUNT_LINK_KEY)
-		k->u.link_key = NULL;
-	      gomp_remove_var (walk->dev, k);
-	    }
-
-	  walk->dev = NULL;
-	  walk->base_dev = NULL;
-	}
+      walk->dev = NULL;
+      walk->base_dev = NULL;
     }
 
   gomp_mutex_unlock (&goacc_thread_lock);