From 4a89454dcd75ebc44e557012c2d007934836f9de Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 10 Aug 2001 22:53:32 +0000 Subject: - Close races with signals and other AST's being triggered while we are in the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly) --- sys/alpha/include/cpu.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'sys/alpha/include/cpu.h') diff --git a/sys/alpha/include/cpu.h b/sys/alpha/include/cpu.h index e901cb1..69ed2ea 100644 --- a/sys/alpha/include/cpu.h +++ b/sys/alpha/include/cpu.h @@ -70,20 +70,6 @@ struct clockframe { #define CLKF_PC(framep) TRAPF_PC(&(framep)->cf_tf) /* - * Arrange to handle pending profiling ticks before returning to user mode. - * - * XXX this is now poorly named and implemented. It used to handle only a - * single tick and the PS_OWEUPC flag served as a counter. Now there is a - * counter in the proc table and flag isn't really necessary. - */ -#define need_proftick(p) do { \ - mtx_lock_spin(&sched_lock); \ - (p)->p_sflag |= PS_OWEUPC; \ - aston(p); \ - mtx_unlock_spin(&sched_lock); \ -} while (0) - -/* * CTL_MACHDEP definitions. */ #define CPU_CONSDEV 1 /* dev_t: console terminal device */ -- cgit v1.1