X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=README;h=ca23d43fe3bee6b5e62d5cfcd0489bb93c7ffc2b;hb=36bc70a84250927ba68d5096a0a9740aec157f9b;hp=f9437dba2857856b726cc4539b6deeafaf09f668;hpb=64c4cafd597aff7423be003dcf41735904126f66;p=urcu.git

diff --git a/README b/README
index f9437db..ca23d43 100644
--- a/README
+++ b/README
@@ -9,20 +9,24 @@ BUILDING
 	make
 	make install
 
-	Note:	Forcing 32-bit build:
-		* CFLAGS=-m32 ./configure
+	Hints:	Forcing 32-bit build:
+		* CFLAGS="-m32 -g -O2" ./configure
 
 		Forcing 64-bit build:
-		* CFLAGS=-m64 ./configure
+		* CFLAGS="-m64 -g -O2" ./configure
+
+		Forcing a 32-bit build with 386 backward compatibility:
+		* CFLAGS="-m32 -g -O2" ./configure --host=i386-pc-linux-gnu
+
+		Forcing a 32-bit build for Sparcv9 (typical for Sparc v9)
+		* CFLAGS="-m32 -Wa,-Av9a -g -O2" ./configure
 
 ARCHITECTURES SUPPORTED
 -----------------------
 
-Currently, x86 (only P6+), x86 64, PowerPC 32/64 and S390 are
-supported. The current use of sys_futex() makes it Linux-dependent, although
-this portability limitation might go away in a near future by using the pthread
-cond vars. Also, the restriction against i386, i486 and Pentium might go away if
-we integrate some of glibc runtime CPU-detection tests.
+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.
 
 QUICK START GUIDE
 -----------------
@@ -98,11 +102,20 @@ Writing
 Usage of liburcu-defer
 
 	* #include <urcu-defer.h>
-	* Link with "-lurcu-defer"
-	* Provides call_rcu() primitive to enqueue delayed callbacks. Queued
+	* Link with "-lurcu-defer", and also with one of the urcu library
+	  (either urcu, urcu-bp, urcu-mb or urcu-qsbr).
+	* Provides defer_rcu() primitive to enqueue delayed callbacks. Queued
 	  callbacks are executed in batch periodically after a grace period.
-	  Do _not_ use call_rcu() within a read-side critical section, because
+	  Do _not_ use defer_rcu() within a read-side critical section, because
 	  it may call synchronize_rcu() if the thread queue is full.
+	* Provides defer_rcu_ratelimit() primitive, which acts just like
+	  defer_rcu(), but takes an additional rate limiter callback forcing
+	  synchronized callback execution of the limiter returns non-zero.
+	* Requires that rcu_defer_barrier() must be called in library destructor
+	  if a library queues callbacks and is expected to be unloaded with
+	  dlclose().
+	* Its API is currently experimental. It may change in future library
+	  releases.
 
 Being careful with signals
 
@@ -136,3 +149,13 @@ Usage of DEBUG_YIELD
 
 	DEBUG_YIELD is used to add random delays in the code for testing
 	purposes.
+
+SMP support
+
+	By default the library is configured to use synchronization primitives
+	adequate for SMP systems. On uniprocessor systems, support for SMP
+	systems can be disabled with:
+
+		./configure --disable-smp-support
+
+	theoretically yielding slightly better performance.