docs: Document simple trace backend thread-safety limitation

Submitted by Stefan Hajnoczi on Jan. 21, 2011, 9:26 a.m.

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Message ID 1295601999-14280-1-git-send-email-stefanha@linux.vnet.ibm.com
State New
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Stefan Hajnoczi Jan. 21, 2011, 9:26 a.m.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 docs/tracing.txt |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

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diff --git a/docs/tracing.txt b/docs/tracing.txt
index 963c504..d2499d9 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -133,6 +133,11 @@  source tree.  It may not be as powerful as platform-specific or third-party
 trace backends but it is portable.  This is the recommended trace backend
 unless you have specific needs for more advanced backends.
 
+This trace backend is not thread-safe.  In many cases this is not an issue
+since the QEMU global mutex covers much of the codebase.  Consider this
+limitation when tracing utility functions that may be called from worker
+threads with no synchronization.
+
 ==== Monitor commands ====
 
 * info trace