/* $NetBSD: kern_synch.c,v 1.194 2007/08/06 11:48:23 yamt Exp $ */ /*- * Copyright (c) 1999, 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center, by Charles M. Hannum, Andrew Doran and * Daniel Sieger. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 1982, 1986, 1990, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_synch.c 8.9 (Berkeley) 5/19/95 */ #include __KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.194 2007/08/06 11:48:23 yamt Exp $"); #include "opt_kstack.h" #include "opt_lockdebug.h" #include "opt_multiprocessor.h" #include "opt_perfctrs.h" #define __MUTEX_PRIVATE #include #include #include #include #if defined(PERFCTRS) #include #endif #include #include #include #include #include #include #include #include callout_t sched_pstats_ch; unsigned int sched_pstats_ticks; kcondvar_t lbolt; /* once a second sleep address */ static void sched_unsleep(struct lwp *); static void sched_changepri(struct lwp *, pri_t); static void sched_lendpri(struct lwp *, pri_t); syncobj_t sleep_syncobj = { SOBJ_SLEEPQ_SORTED, sleepq_unsleep, sleepq_changepri, sleepq_lendpri, syncobj_noowner, }; syncobj_t sched_syncobj = { SOBJ_SLEEPQ_SORTED, sched_unsleep, sched_changepri, sched_lendpri, syncobj_noowner, }; /* * During autoconfiguration or after a panic, a sleep will simply lower the * priority briefly to allow interrupts, then return. The priority to be * used (safepri) is machine-dependent, thus this value is initialized and * maintained in the machine-dependent layers. This priority will typically * be 0, or the lowest priority that is safe for use on the interrupt stack; * it can be made higher to block network software interrupts after panics. */ int safepri; /* * OBSOLETE INTERFACE * * General sleep call. Suspends the current process until a wakeup is * performed on the specified identifier. The process will then be made * runnable with the specified priority. Sleeps at most timo/hz seconds (0 * means no timeout). If pri includes PCATCH flag, signals are checked * before and after sleeping, else signals are not checked. Returns 0 if * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a * signal needs to be delivered, ERESTART is returned if the current system * call should be restarted if possible, and EINTR is returned if the system * call should be interrupted by the signal (return EINTR). * * The interlock is held until we are on a sleep queue. The interlock will * be locked before returning back to the caller unless the PNORELOCK flag * is specified, in which case the interlock will always be unlocked upon * return. */ int ltsleep(wchan_t ident, pri_t priority, const char *wmesg, int timo, volatile struct simplelock *interlock) { struct lwp *l = curlwp; sleepq_t *sq; int error; if (sleepq_dontsleep(l)) { (void)sleepq_abort(NULL, 0); if ((priority & PNORELOCK) != 0) simple_unlock(interlock); return 0; } sq = sleeptab_lookup(&sleeptab, ident); sleepq_enter(sq, l); sleepq_enqueue(sq, priority & PRIMASK, ident, wmesg, &sleep_syncobj); if (interlock != NULL) { LOCK_ASSERT(simple_lock_held(interlock)); simple_unlock(interlock); } error = sleepq_block(timo, priority & PCATCH); if (interlock != NULL && (priority & PNORELOCK) == 0) simple_lock(interlock); return error; } int mtsleep(wchan_t ident, pri_t priority, const char *wmesg, int timo, kmutex_t *mtx) { struct lwp *l = curlwp; sleepq_t *sq; int error; if (sleepq_dontsleep(l)) { (void)sleepq_abort(mtx, (priority & PNORELOCK) != 0); return 0; } sq = sleeptab_lookup(&sleeptab, ident); sleepq_enter(sq, l); sleepq_enqueue(sq, priority & PRIMASK, ident, wmesg, &sleep_syncobj); mutex_exit(mtx); error = sleepq_block(timo, priority & PCATCH); if ((priority & PNORELOCK) == 0) mutex_enter(mtx); return error; } /* * General sleep call for situations where a wake-up is not expected. */ int kpause(const char *wmesg, bool intr, int timo, kmutex_t *mtx) { struct lwp *l = curlwp; sleepq_t *sq; int error; if (sleepq_dontsleep(l)) return sleepq_abort(NULL, 0); if (mtx != NULL) mutex_exit(mtx); sq = sleeptab_lookup(&sleeptab, l); sleepq_enter(sq, l); sleepq_enqueue(sq, sched_kpri(l), l, wmesg, &sleep_syncobj); error = sleepq_block(timo, intr); if (mtx != NULL) mutex_enter(mtx); return error; } /* * OBSOLETE INTERFACE * * Make all processes sleeping on the specified identifier runnable. */ void wakeup(wchan_t ident) { sleepq_t *sq; if (cold) return; sq = sleeptab_lookup(&sleeptab, ident); sleepq_wake(sq, ident, (u_int)-1); } /* * OBSOLETE INTERFACE * * Make the highest priority process first in line on the specified * identifier runnable. */ void wakeup_one(wchan_t ident) { sleepq_t *sq; if (cold) return; sq = sleeptab_lookup(&sleeptab, ident); sleepq_wake(sq, ident, 1); } /* * General yield call. Puts the current process back on its run queue and * performs a voluntary context switch. Should only be called when the * current process explicitly requests it (eg sched_yield(2) in compat code). */ void yield(void) { struct lwp *l = curlwp; KERNEL_UNLOCK_ALL(l, &l->l_biglocks); lwp_lock(l); KASSERT(lwp_locked(l, &l->l_cpu->ci_schedstate.spc_lwplock)); KASSERT(l->l_stat == LSONPROC); l->l_priority = l->l_usrpri; (void)mi_switch(l); KERNEL_LOCK(l->l_biglocks, l); } /* * General preemption call. Puts the current process back on its run queue * and performs an involuntary context switch. */ void preempt(void) { struct lwp *l = curlwp; KERNEL_UNLOCK_ALL(l, &l->l_biglocks); lwp_lock(l); KASSERT(lwp_locked(l, &l->l_cpu->ci_schedstate.spc_lwplock)); KASSERT(l->l_stat == LSONPROC); l->l_priority = l->l_usrpri; l->l_nivcsw++; (void)mi_switch(l); KERNEL_LOCK(l->l_biglocks, l); } /* * Compute the amount of time during which the current lwp was running. * * - update l_rtime unless it's an idle lwp. * - update spc_runtime for the next lwp. */ static inline void updatertime(struct lwp *l, struct schedstate_percpu *spc) { struct timeval tv; long s, u; if ((l->l_flag & LW_IDLE) != 0) { microtime(&spc->spc_runtime); return; } microtime(&tv); u = l->l_rtime.tv_usec + (tv.tv_usec - spc->spc_runtime.tv_usec); s = l->l_rtime.tv_sec + (tv.tv_sec - spc->spc_runtime.tv_sec); if (u < 0) { u += 1000000; s--; } else if (u >= 1000000) { u -= 1000000; s++; } l->l_rtime.tv_usec = u; l->l_rtime.tv_sec = s; spc->spc_runtime = tv; } /* * The machine independent parts of context switch. * * Returns 1 if another LWP was actually run. */ int mi_switch(struct lwp *l) { struct schedstate_percpu *spc; struct lwp *newl; int retval, oldspl; KASSERT(lwp_locked(l, NULL)); LOCKDEBUG_BARRIER(l->l_mutex, 1); #ifdef KSTACK_CHECK_MAGIC kstack_check_magic(l); #endif /* * It's safe to read the per CPU schedstate unlocked here, as all we * are after is the run time and that's guarenteed to have been last * updated by this CPU. */ KDASSERT(l->l_cpu == curcpu()); /* * Process is about to yield the CPU; clear the appropriate * scheduling flags. */ spc = &l->l_cpu->ci_schedstate; newl = NULL; if (l->l_switchto != NULL) { newl = l->l_switchto; l->l_switchto = NULL; } /* Count time spent in current system call */ SYSCALL_TIME_SLEEP(l); /* * XXXSMP If we are using h/w performance counters, * save context. */ #if PERFCTRS if (PMC_ENABLED(l->l_proc)) { pmc_save_context(l->l_proc); } #endif updatertime(l, spc); /* * If on the CPU and we have gotten this far, then we must yield. */ mutex_spin_enter(spc->spc_mutex); spc->spc_flags &= ~SPCF_SWITCHCLEAR; KASSERT(l->l_stat != LSRUN); if (l->l_stat == LSONPROC) { KASSERT(lwp_locked(l, &spc->spc_lwplock)); if ((l->l_flag & LW_IDLE) == 0) { l->l_stat = LSRUN; lwp_setlock(l, spc->spc_mutex); sched_enqueue(l, true); } else l->l_stat = LSIDL; } /* * Let sched_nextlwp() select the LWP to run the CPU next. * If no LWP is runnable, switch to the idle LWP. */ if (newl == NULL) { newl = sched_nextlwp(); if (newl != NULL) { sched_dequeue(newl); KASSERT(lwp_locked(newl, spc->spc_mutex)); newl->l_stat = LSONPROC; newl->l_cpu = l->l_cpu; newl->l_flag |= LW_RUNNING; lwp_setlock(newl, &spc->spc_lwplock); } else { newl = l->l_cpu->ci_data.cpu_idlelwp; newl->l_stat = LSONPROC; newl->l_flag |= LW_RUNNING; } spc->spc_curpriority = newl->l_usrpri; newl->l_priority = newl->l_usrpri; cpu_did_resched(); } if (l != newl) { struct lwp *prevlwp; /* * If the old LWP has been moved to a run queue above, * drop the general purpose LWP lock: it's now locked * by the scheduler lock. * * Otherwise, drop the scheduler lock. We're done with * the run queues for now. */ if (l->l_mutex == spc->spc_mutex) { mutex_spin_exit(&spc->spc_lwplock); } else { mutex_spin_exit(spc->spc_mutex); } /* Unlocked, but for statistics only. */ uvmexp.swtch++; /* Save old VM context. */ pmap_deactivate(l); /* Switch to the new LWP.. */ l->l_ncsw++; l->l_flag &= ~LW_RUNNING; oldspl = MUTEX_SPIN_OLDSPL(l->l_cpu); prevlwp = cpu_switchto(l, newl); /* * .. we have switched away and are now back so we must * be the new curlwp. prevlwp is who we replaced. */ curlwp = l; if (prevlwp != NULL) { curcpu()->ci_mtx_oldspl = oldspl; lwp_unlock(prevlwp); } else { splx(oldspl); } /* Restore VM context. */ pmap_activate(l); retval = 1; } else { /* Nothing to do - just unlock and return. */ mutex_spin_exit(spc->spc_mutex); lwp_unlock(l); retval = 0; } KASSERT(l == curlwp); KASSERT(l->l_stat == LSONPROC); /* * XXXSMP If we are using h/w performance counters, restore context. */ #if PERFCTRS if (PMC_ENABLED(l->l_proc)) { pmc_restore_context(l->l_proc); } #endif /* * We're running again; record our new start time. We might * be running on a new CPU now, so don't use the cached * schedstate_percpu pointer. */ SYSCALL_TIME_WAKEUP(l); KDASSERT(l->l_cpu == curcpu()); LOCKDEBUG_BARRIER(NULL, 1); return retval; } /* * Change process state to be runnable, placing it on the run queue if it is * in memory, and awakening the swapper if it isn't in memory. * * Call with the process and LWP locked. Will return with the LWP unlocked. */ void setrunnable(struct lwp *l) { struct proc *p = l->l_proc; sigset_t *ss; KASSERT((l->l_flag & LW_IDLE) == 0); KASSERT(mutex_owned(&p->p_smutex)); KASSERT(lwp_locked(l, NULL)); switch (l->l_stat) { case LSSTOP: /* * If we're being traced (possibly because someone attached us * while we were stopped), check for a signal from the debugger. */ if ((p->p_slflag & PSL_TRACED) != 0 && p->p_xstat != 0) { if ((sigprop[p->p_xstat] & SA_TOLWP) != 0) ss = &l->l_sigpend.sp_set; else ss = &p->p_sigpend.sp_set; sigaddset(ss, p->p_xstat); signotify(l); } p->p_nrlwps++; break; case LSSUSPENDED: l->l_flag &= ~LW_WSUSPEND; p->p_nrlwps++; cv_broadcast(&p->p_lwpcv); break; case LSSLEEP: KASSERT(l->l_wchan != NULL); break; default: panic("setrunnable: lwp %p state was %d", l, l->l_stat); } /* * If the LWP was sleeping interruptably, then it's OK to start it * again. If not, mark it as still sleeping. */ if (l->l_wchan != NULL) { l->l_stat = LSSLEEP; /* lwp_unsleep() will release the lock. */ lwp_unsleep(l); return; } /* * If the LWP is still on the CPU, mark it as LSONPROC. It may be * about to call mi_switch(), in which case it will yield. */ if ((l->l_flag & LW_RUNNING) != 0) { l->l_stat = LSONPROC; l->l_slptime = 0; lwp_unlock(l); return; } /* * Set the LWP runnable. If it's swapped out, we need to wake the swapper * to bring it back in. Otherwise, enter it into a run queue. */ if (l->l_mutex != l->l_cpu->ci_schedstate.spc_mutex) { spc_lock(l->l_cpu); lwp_unlock_to(l, l->l_cpu->ci_schedstate.spc_mutex); } sched_setrunnable(l); l->l_stat = LSRUN; l->l_slptime = 0; if (l->l_flag & LW_INMEM) { sched_enqueue(l, false); resched_cpu(l); lwp_unlock(l); } else { lwp_unlock(l); uvm_kick_scheduler(); } } /* * suspendsched: * * Convert all non-L_SYSTEM LSSLEEP or LSRUN LWPs to LSSUSPENDED. */ void suspendsched(void) { CPU_INFO_ITERATOR cii; struct cpu_info *ci; struct lwp *l; struct proc *p; /* * We do this by process in order not to violate the locking rules. */ mutex_enter(&proclist_mutex); PROCLIST_FOREACH(p, &allproc) { mutex_enter(&p->p_smutex); if ((p->p_flag & PK_SYSTEM) != 0) { mutex_exit(&p->p_smutex); continue; } p->p_stat = SSTOP; LIST_FOREACH(l, &p->p_lwps, l_sibling) { if (l == curlwp) continue; lwp_lock(l); /* * Set L_WREBOOT so that the LWP will suspend itself * when it tries to return to user mode. We want to * try and get to get as many LWPs as possible to * the user / kernel boundary, so that they will * release any locks that they hold. */ l->l_flag |= (LW_WREBOOT | LW_WSUSPEND); if (l->l_stat == LSSLEEP && (l->l_flag & LW_SINTR) != 0) { /* setrunnable() will release the lock. */ setrunnable(l); continue; } lwp_unlock(l); } mutex_exit(&p->p_smutex); } mutex_exit(&proclist_mutex); /* * Kick all CPUs to make them preempt any LWPs running in user mode. * They'll trap into the kernel and suspend themselves in userret(). */ for (CPU_INFO_FOREACH(cii, ci)) cpu_need_resched(ci, 0); } /* * sched_kpri: * * Scale a priority level to a kernel priority level, usually * for an LWP that is about to sleep. */ pri_t sched_kpri(struct lwp *l) { /* * Scale user priorities (127 -> 50) up to kernel priorities * in the range (49 -> 8). Reserve the top 8 kernel priorities * for high priority kthreads. Kernel priorities passed in * are left "as is". XXX This is somewhat arbitrary. */ static const uint8_t kpri_tab[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 38, 38, 39, 39, 40, 40, 41, 41, 42, 42, 43, 44, 44, 45, 45, 46, 46, 47, 47, 48, 48, 49, 49, }; return (pri_t)kpri_tab[l->l_usrpri]; } /* * sched_unsleep: * * The is called when the LWP has not been awoken normally but instead * interrupted: for example, if the sleep timed out. Because of this, * it's not a valid action for running or idle LWPs. */ static void sched_unsleep(struct lwp *l) { lwp_unlock(l); panic("sched_unsleep"); } inline void resched_cpu(struct lwp *l) { struct cpu_info *ci; const pri_t pri = lwp_eprio(l); /* * 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 != NULL) ? l->l_cpu : curcpu(); if (pri < ci->ci_schedstate.spc_curpriority) cpu_need_resched(ci, 0); } static void sched_changepri(struct lwp *l, pri_t pri) { KASSERT(lwp_locked(l, NULL)); l->l_usrpri = pri; if (l->l_priority < PUSER) return; if (l->l_stat != LSRUN || (l->l_flag & LW_INMEM) == 0) { l->l_priority = pri; return; } KASSERT(lwp_locked(l, l->l_cpu->ci_schedstate.spc_mutex)); sched_dequeue(l); l->l_priority = pri; sched_enqueue(l, false); resched_cpu(l); } static void sched_lendpri(struct lwp *l, pri_t pri) { KASSERT(lwp_locked(l, NULL)); if (l->l_stat != LSRUN || (l->l_flag & LW_INMEM) == 0) { l->l_inheritedprio = pri; return; } KASSERT(lwp_locked(l, l->l_cpu->ci_schedstate.spc_mutex)); sched_dequeue(l); l->l_inheritedprio = pri; sched_enqueue(l, false); resched_cpu(l); } struct lwp * 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) /* * sched_pstats: * * Update process statistics and check CPU resource allocation. * Call scheduler-specific hook to eventually adjust process/LWP * priorities. * * XXXSMP This needs to be reorganised in order to reduce the locking * burden. */ /* ARGSUSED */ void sched_pstats(void *arg) { struct rlimit *rlim; struct lwp *l; struct proc *p; int minslp, sig, clkhz; long runtm; sched_pstats_ticks++; mutex_enter(&proclist_mutex); PROCLIST_FOREACH(p, &allproc) { /* * 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. */ minslp = 2; mutex_enter(&p->p_smutex); mutex_spin_enter(&p->p_stmutex); runtm = p->p_rtime.tv_sec; LIST_FOREACH(l, &p->p_lwps, l_sibling) { if ((l->l_flag & LW_IDLE) != 0) continue; lwp_lock(l); runtm += l->l_rtime.tv_sec; l->l_swtime++; if (l->l_stat == LSSLEEP || l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED) { l->l_slptime++; minslp = min(minslp, l->l_slptime); } else minslp = 0; lwp_unlock(l); /* * p_pctcpu is only for ps. */ l->l_pctcpu = (l->l_pctcpu * ccpu) >> FSHIFT; if (l->l_slptime < 1) { clkhz = stathz != 0 ? stathz : hz; #if (FSHIFT >= CCPU_SHIFT) l->l_pctcpu += (clkhz == 100) ? ((fixpt_t)l->l_cpticks) << (FSHIFT - CCPU_SHIFT) : 100 * (((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT)) / clkhz; #else l->l_pctcpu += ((FSCALE - ccpu) * (l->l_cpticks * FSCALE / clkhz)) >> FSHIFT; #endif l->l_cpticks = 0; } } p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT; sched_pstats_hook(p, minslp); mutex_spin_exit(&p->p_stmutex); /* * Check if the process exceeds its CPU resource allocation. * If over max, kill it. */ rlim = &p->p_rlimit[RLIMIT_CPU]; sig = 0; if (runtm >= rlim->rlim_cur) { if (runtm >= rlim->rlim_max) sig = SIGKILL; else { sig = SIGXCPU; if (rlim->rlim_cur < rlim->rlim_max) rlim->rlim_cur += 5; } } mutex_exit(&p->p_smutex); if (sig) { psignal(p, sig); } } mutex_exit(&proclist_mutex); uvm_meter(); cv_wakeup(&lbolt); callout_schedule(&sched_pstats_ch, hz); } void sched_init(void) { cv_init(&lbolt, "lbolt"); callout_init(&sched_pstats_ch, 0); callout_setfunc(&sched_pstats_ch, sched_pstats, NULL); sched_setup(); sched_pstats(NULL); }