linux-2.6.0/arch/um/kernel/smp.c
/*
 * This is called when we want to synchronize with
 * bottom half handlers. We need to wait until
 * no other CPU is executing any bottom half handler.
 *
 * Don't wait if we're already running in an interrupt
 * context or are inside a bh handler. 
 */
This is called when we want to synchronize with
bottom half handlers. We need to wait until
no other CPU is executing any bottom half handler.

Don't wait if we're already running in an interrupt
context or are inside a bh handler.
This is called when we want to synchronize with bottom half handlers . We need to wait until no other CPU is executing any bottom half handler . Don ' t wait if we ' re already running in an interrupt context or are inside a bh handler .
void synchronize_bh(void)
{
	if (atomic_read(&global_bh_count) && !in_interrupt())
		wait_on_bh();
}
void synchronize_bh ( void ) { if ( atomic_read ( & global_bh_count ) && ! in_interrupt ( ) ) wait_on_bh ( ) ; }
This is called when we want to synchronize with
 bottom half handlers.
This is called when we want to synchronize with bottom half handlers .