X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=README;h=b6d2ae48d0b3365ccd0aa4344bc95f24ed6daef3;hb=f9edede0c2229e5d92d0480d358eb2d14f2a8229;hp=2687382e2bc785ac9db704f4f01aea2eab7ce18e;hpb=ee39cfb61d2a389db3342751762412f332a3e851;p=urcu.git

diff --git a/README b/README
index 2687382..b6d2ae4 100644
--- a/README
+++ b/README
@@ -24,9 +24,23 @@ BUILDING
 ARCHITECTURES SUPPORTED
 -----------------------
 
-Currently, x86 (i386, i486, i586, i686), x86 64-bit, PowerPC 32/64, S390, S390x
-and Sparcv9 32/64 are supported. Only tested on Linux so far, but should
-theoretically work on other operating systems.
+Currently, x86 (i386, i486, i586, i686), x86 64-bit, PowerPC 32/64, S390, S390x,
+ARM, Alpha, ia64 and Sparcv9 32/64 are supported. Only tested on Linux so
+far, but should theoretically work on other operating systems.
+
+ARM depends on running a Linux kernel 2.6.15 or better.
+
+The gcc compiler versions 3.3, 3.4, 4.0, 4.1, 4.2, 4.3, 4.4 and 4.5 are
+supported, with the following exceptions:
+
+- gcc 3.3 and 3.4 have a bug that prevents them from generating volatile
+  accesses to offsets in a TLS structure on 32-bit x86. These versions are
+  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
+- Alpha, ia64 and ARM architectures depend on 4.x gcc with atomic builtins
+  support.
+
 
 QUICK START GUIDE
 -----------------
@@ -176,3 +190,17 @@ SMP support
 		./configure --disable-smp-support
 
 	theoretically yielding slightly better performance.
+
+Interaction with fork()
+
+	Special care must be taken for applications performing fork() without
+	any following exec(). This is caused by the fact that Linux only clones
+	the thread calling fork(), and thus never replicates any of the other
+	parent thread into the child process. Most liburcu implementations
+	require that all registrations (as reader, defer_rcu and call_rcu
+	threads) should be released before a fork() is performed, except for the
+	rather common scenario where fork() is immediately followed by exec() in
+	the child process. The only implementation not subject to that rule is
+	liburcu-bp, which is designed to handle this case by requiring a call to
+	synchronize_rcu() following the fork() in the child before any new
+	thread is created.