From 73f3b7bb31d79b6beb33b848baa6b9742f50662e Mon Sep 17 00:00:00 2001 From: rmind Date: Wed, 2 Jul 2008 19:44:10 +0000 Subject: [PATCH] Remove outdated comments, and historical CCPU_SHIFT. Make resched_cpu static, const-ify ccpu. Note: resched_cpu is not correct, should be revisited. OK by . --- sys/kern/kern_synch.c | 60 ++++++++----------------------------------- sys/sys/lwp.h | 3 +-- sys/sys/sched.h | 3 +-- 3 files changed, 12 insertions(+), 54 deletions(-) diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c index 499d41524f49..c2be5c75f606 100644 --- a/sys/kern/kern_synch.c +++ b/sys/kern/kern_synch.c @@ -1,4 +1,4 @@ -/* $NetBSD: kern_synch.c,v 1.249 2008/07/02 19:38:37 rmind Exp $ */ +/* $NetBSD: kern_synch.c,v 1.250 2008/07/02 19:44:10 rmind Exp $ */ /*- * Copyright (c) 1999, 2000, 2004, 2006, 2007, 2008 The NetBSD Foundation, Inc. @@ -68,7 +68,7 @@ */ #include -__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.249 2008/07/02 19:38:37 rmind Exp $"); +__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.250 2008/07/02 19:44:10 rmind Exp $"); #include "opt_kstack.h" #include "opt_perfctrs.h" @@ -101,6 +101,7 @@ __KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.249 2008/07/02 19:38:37 rmind Exp $ static u_int sched_unsleep(struct lwp *, bool); static void sched_changepri(struct lwp *, pri_t); static void sched_lendpri(struct lwp *, pri_t); +static void resched_cpu(struct lwp *); syncobj_t sleep_syncobj = { SOBJ_SLEEPQ_SORTED, @@ -1066,30 +1067,12 @@ sched_unsleep(struct lwp *l, bool cleanup) panic("sched_unsleep"); } -void +static void resched_cpu(struct lwp *l) { - struct cpu_info *ci; + struct cpu_info *ci = ci = l->l_cpu; - /* - * XXXSMP - * Since l->l_cpu persists across a context switch, - * this gives us *very weak* processor affinity, in - * that we notify the CPU on which the process last - * ran that it should try to switch. - * - * This does not guarantee that the process will run on - * that processor next, because another processor might - * grab it the next time it performs a context switch. - * - * This also does not handle the case where its last - * CPU is running a higher-priority process, but every - * other CPU is running a lower-priority process. There - * are ways to handle this situation, but they're not - * currently very pretty, and we also need to weigh the - * cost of moving a process from one CPU to another. - */ - ci = l->l_cpu; + KASSERT(lwp_locked(l, NULL)); if (lwp_eprio(l) > ci->ci_schedstate.spc_curpriority) cpu_need_resched(ci, 0); } @@ -1135,22 +1118,8 @@ syncobj_noowner(wchan_t wchan) return NULL; } -/* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ -fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ - -/* - * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the - * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below - * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). - * - * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: - * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). - * - * If you dont want to bother with the faster/more-accurate formula, you - * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate - * (more general) method of calculating the %age of CPU used by a process. - */ -#define CCPU_SHIFT (FSHIFT + 1) +/* Decay 95% of proc::p_pctcpu in 60 seconds, ccpu = exp(-1/20) */ +const fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* * sched_pstats: @@ -1180,9 +1149,8 @@ sched_pstats(void *arg) continue; /* - * Increment time in/out of memory and sleep time (if - * sleeping). We ignore overflow; with 16-bit int's - * (remember them?) overflow takes 45 days. + * Increment time in/out of memory and sleep + * time (if sleeping), ignore overflow. */ mutex_enter(p->p_lock); runtm = p->p_rtime.sec; @@ -1201,16 +1169,8 @@ sched_pstats(void *arg) lpctcpu = l->l_pctcpu; lcpticks = atomic_swap_uint(&l->l_cpticks, 0); -#if (FSHIFT >= CCPU_SHIFT) - lpctcpu += (clkhz == 100) ? - ((fixpt_t)lcpticks) << - (FSHIFT - CCPU_SHIFT) : - 100 * (((fixpt_t) p->p_cpticks) - << (FSHIFT - CCPU_SHIFT)) / clkhz; -#else lpctcpu += ((FSCALE - ccpu) * (lcpticks * FSCALE / clkhz)) >> FSHIFT; -#endif l->l_pctcpu = lpctcpu; } /* Calculating p_pctcpu only for ps(1) */ diff --git a/sys/sys/lwp.h b/sys/sys/lwp.h index a61a36ba973e..0109c3f87497 100644 --- a/sys/sys/lwp.h +++ b/sys/sys/lwp.h @@ -1,4 +1,4 @@ -/* $NetBSD: lwp.h,v 1.103 2008/07/02 19:38:37 rmind Exp $ */ +/* $NetBSD: lwp.h,v 1.104 2008/07/02 19:44:10 rmind Exp $ */ /*- * Copyright (c) 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc. @@ -281,7 +281,6 @@ void startlwp(void *); void upcallret(lwp_t *); void lwp_exit(lwp_t *) __dead; void lwp_exit_switchaway(lwp_t *); -lwp_t *proc_representative_lwp(struct proc *, int *, int); int lwp_suspend(lwp_t *, lwp_t *); int lwp_create1(lwp_t *, const void *, size_t, u_long, lwpid_t *); void lwp_update_creds(lwp_t *); diff --git a/sys/sys/sched.h b/sys/sys/sched.h index cfdc0abf1ff3..9a54d6ca88d5 100644 --- a/sys/sys/sched.h +++ b/sys/sys/sched.h @@ -1,4 +1,4 @@ -/* $NetBSD: sched.h,v 1.62 2008/06/22 14:00:11 ad Exp $ */ +/* $NetBSD: sched.h,v 1.63 2008/07/02 19:44:10 rmind Exp $ */ /*- * Copyright (c) 1999, 2000, 2001, 2002, 2007, 2008 The NetBSD Foundation, Inc. @@ -265,7 +265,6 @@ void sched_print_runqueue(void (*pr)(const char *, ...)); bool kpreempt(uintptr_t); void preempt(void); int mi_switch(struct lwp *); -void resched_cpu(struct lwp *); void updatertime(lwp_t *, const struct bintime *); void sched_idle(void);