[PATCH] xentrace: Disable tracing, then read records one more time.

[PATCH] xentrace: Disable tracing, then read records one more time.

[George Dunlap]

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When interrupted, first disable tracing, then read through the records
one last time.

Without this patch, it's possible to get traces which interact (such as runstate
changes) on processors with higher numbers, while missing the corresponding
traces generated on lower-numbered processors.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

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diff -r d9dcb3ecebba tools/xentrace/xentrace.c
--- a/tools/xentrace/xentrace.c	Tue Dec 15 14:40:17 2009 +0000
+++ b/tools/xentrace/xentrace.c	Wed Jan 06 12:02:54 2010 +0000
@@ -638,7 +683,9 @@
     unsigned long size;          /* size of a single trace buffer            */
 
     unsigned long data_size;
 
+    int last_read = 1;
+
     /* prepare to listen for VIRQ_TBUF */
     event_init();
 
@@ -725,14 +774,22 @@
         }
 
         if ( interrupted )
-            break;
+        {
+            if ( last_read )
+            {
+                /* Disable tracing, then read through all the buffers one last time */
+                if ( opts.disable_tracing )
+                    disable_tbufs();
+                last_read = 0;
+                continue;
+            }
+            else
+                break;
+        }
 
         wait_for_event_or_timeout(opts.poll_sleep);
     }
 
-    if ( opts.disable_tracing )
-        disable_tbufs();
-
     if ( opts.memory_buffer )
         membuf_dump();
 

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