X-Git-Url: https://git.lttng.org/?p=urcu.git;a=blobdiff_plain;f=README;h=e3800faad2d10cc5789c0a622c14f5ade9962ae1;hp=a6e29c875de973ec9020cad76de9e28aa564fdf2;hb=5a2141a73185fb1aaaceb73f8239a7efb81c16e6;hpb=26ba798aa19e32441020728f2f5fd90df87d4175

diff --git a/README b/README
index a6e29c8..e3800fa 100644
--- a/README
+++ b/README
@@ -8,6 +8,7 @@ BUILDING
 	./configure
 	make
 	make install
+	ldconfig
 
 	Hints:	Forcing 32-bit build:
 		* CFLAGS="-m32 -g -O2" ./configure
@@ -38,6 +39,8 @@ supported, with the following exceptions:
   therefore not compatible with liburcu on x86 32-bit (i386, i486, i586, i686).
   The problem has been reported to the gcc community:
     http://www.mail-archive.com/gcc-bugs@gcc.gnu.org/msg281255.html
+- gcc 3.3 cannot match the "xchg" instruction on 32-bit x86 build.
+  See: http://kerneltrap.org/node/7507
 - Alpha, ia64 and ARM architectures depend on 4.x gcc with atomic builtins
   support.
 
@@ -184,6 +187,15 @@ Interaction with mutexes
 	mutex in its dependency chain) should not be acquired from within a RCU
 	read-side critical section.
 
+	This is especially important to understand in the context of the
+	QSBR flavor: a registered reader thread being "online" by
+	default should be considered as within a RCU read-side critical
+	section unless explicitly put "offline". Therefore, if
+	synchronize_rcu() is called with a mutex held, this mutex, as
+	well as any mutex which has this mutex in its dependency chain
+	should only be taken when the RCU reader thread is "offline"
+	(this can be performed by calling rcu_thread_offline()).
+
 Usage of DEBUG_RCU
 
 	DEBUG_RCU is used to add internal debugging self-checks to the