This patch modfies i386 to add a flag to sa_flags in sigaction that will 
cause the signal handler to not be called (but all other side effects to 
occur).  This may seem unusual, but signals are often used between 
threads to wake each other up, the signal handler is just a dummy and is 
pure overhead.  With this patch, if the flag is set, the signal handler 
won't get called (thus saving the overhead of going in and out of 
userland for the handler), but it will still wake up sigsuspend() and 
select().  The beauty of this is the flag will be ignored on kernels 
without it, so it will still work, with just lower performance.

-Corey