From: Mathieu Desnoyers Date: Tue, 15 Sep 2009 18:24:34 +0000 (-0400) Subject: update README X-Git-Tag: v0.1~95 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=cee02f0ab0a6766662490f2d815d487c098c17b1;p=userspace-rcu.git update README - Add comment about new threads and signals - document DEBUG_RCU Signed-off-by: Mathieu Desnoyers --- diff --git a/README b/README index ae8b661..0ec723d 100644 --- a/README +++ b/README @@ -39,11 +39,20 @@ Being careful with signals signal(7). To ensure the Userspace RCU library does not use signals, define CONFIG_URCU_AVOID_SIGNALS at compile-time. + Read-side critical sections can sit in a signal handler. Be careful, + however, to disable these signals between thread creation and calls to + rcu_register_thread(), because a signal handler nesting on an + unregistered thread would not be allowed to call rcu_read_lock(). + Usage of CONFIG_URCU_AVOID_SIGNALS CONFIG_URCU_AVOID_SIGNALS uses full SMP barriers for readers. This eliminates the need for signals but results in slower reads. +Usage of DEBUG_RCU + + DEBUG_RCU is used to add internal debugging self-checks to the + RCU library. This define adds a performance penality when enabled. Usage of DEBUG_YIELD