Date: Sun, 17 Apr 2016 11:04:27 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r298145 - in head/sys: kern sys Message-ID: <201604171104.u3HB4RrG085914@repo.freebsd.org>
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Author: kib Date: Sun Apr 17 11:04:27 2016 New Revision: 298145 URL: https://svnweb.freebsd.org/changeset/base/298145 Log: The struct thread td_estcpu member is only used by the 4BSD scheduler. Move it to the struct td_sched for 4BSD, removing always present field, otherwise unused for ULE. New scheduler method sched_estcpu() returns the estimation for kinfo_proc consumption. As before, it always returns 0 for ULE. Remove sched_tick() scheduler method, unused both by 4BSD and ULE. Update locking comment for the 4BSD struct td_sched, copying it from the same comment for ULE. Spell MAXPRI as PRI_MAX_TIMESHARE in the 4BSD comment. Based on some notes from, and reviewed by: bde Sponsored by: The FreeBSD Foundation Modified: head/sys/kern/kern_clock.c head/sys/kern/kern_proc.c head/sys/kern/sched_4bsd.c head/sys/kern/sched_ule.c head/sys/sys/proc.h head/sys/sys/sched.h Modified: head/sys/kern/kern_clock.c ============================================================================== --- head/sys/kern/kern_clock.c Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/kern/kern_clock.c Sun Apr 17 11:04:27 2016 (r298145) @@ -449,7 +449,6 @@ hardclock_cpu(int usermode) PROC_ITIMUNLOCK(p); } thread_lock(td); - sched_tick(1); td->td_flags |= flags; thread_unlock(td); @@ -539,7 +538,6 @@ hardclock_cnt(int cnt, int usermode) PROC_ITIMUNLOCK(p); } thread_lock(td); - sched_tick(cnt); td->td_flags |= flags; thread_unlock(td); Modified: head/sys/kern/kern_proc.c ============================================================================== --- head/sys/kern/kern_proc.c Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/kern/kern_proc.c Sun Apr 17 11:04:27 2016 (r298145) @@ -855,7 +855,7 @@ fill_kinfo_aggregate(struct proc *p, str FOREACH_THREAD_IN_PROC(p, td) { thread_lock(td); kp->ki_pctcpu += sched_pctcpu(td); - kp->ki_estcpu += td->td_estcpu; + kp->ki_estcpu += sched_estcpu(td); thread_unlock(td); } } @@ -1101,7 +1101,7 @@ fill_kinfo_thread(struct thread *td, str rufetchtd(td, &kp->ki_rusage); kp->ki_runtime = cputick2usec(td->td_rux.rux_runtime); kp->ki_pctcpu = sched_pctcpu(td); - kp->ki_estcpu = td->td_estcpu; + kp->ki_estcpu = sched_estcpu(td); kp->ki_cow = td->td_cow; } Modified: head/sys/kern/sched_4bsd.c ============================================================================== --- head/sys/kern/sched_4bsd.c Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/kern/sched_4bsd.c Sun Apr 17 11:04:27 2016 (r298145) @@ -87,12 +87,14 @@ dtrace_vtime_switch_func_t dtrace_vtime_ /* * The schedulable entity that runs a context. * This is an extension to the thread structure and is tailored to - * the requirements of this scheduler + * the requirements of this scheduler. + * All fields are protected by the scheduler lock. */ struct td_sched { - fixpt_t ts_pctcpu; /* (j) %cpu during p_swtime. */ - int ts_cpticks; /* (j) Ticks of cpu time. */ - int ts_slptime; /* (j) Seconds !RUNNING. */ + fixpt_t ts_pctcpu; /* %cpu during p_swtime. */ + u_int ts_estcpu; /* Estimated cpu utilization. */ + int ts_cpticks; /* Ticks of cpu time. */ + int ts_slptime; /* Seconds !RUNNING. */ int ts_slice; /* Remaining part of time slice. */ int ts_flags; struct runq *ts_runq; /* runq the thread is currently on */ @@ -382,20 +384,20 @@ maybe_preempt(struct thread *td) /* * Constants for digital decay and forget: - * 90% of (td_estcpu) usage in 5 * loadav time + * 90% of (ts_estcpu) usage in 5 * loadav time * 95% of (ts_pctcpu) usage in 60 seconds (load insensitive) * Note that, as ps(1) mentions, this can let percentages * total over 100% (I've seen 137.9% for 3 processes). * - * Note that schedclock() updates td_estcpu and p_cpticks asynchronously. + * Note that schedclock() updates ts_estcpu and p_cpticks asynchronously. * - * We wish to decay away 90% of td_estcpu in (5 * loadavg) seconds. + * We wish to decay away 90% of ts_estcpu in (5 * loadavg) seconds. * That is, the system wants to compute a value of decay such * that the following for loop: * for (i = 0; i < (5 * loadavg); i++) - * td_estcpu *= decay; + * ts_estcpu *= decay; * will compute - * td_estcpu *= 0.1; + * ts_estcpu *= 0.1; * for all values of loadavg: * * Mathematically this loop can be expressed by saying: @@ -559,7 +561,7 @@ schedcpu(void) thread_unlock(td); continue; } - td->td_estcpu = decay_cpu(loadfac, td->td_estcpu); + ts->ts_estcpu = decay_cpu(loadfac, ts->ts_estcpu); resetpriority(td); resetpriority_thread(td); thread_unlock(td); @@ -584,8 +586,8 @@ schedcpu_thread(void) /* * Recalculate the priority of a process after it has slept for a while. - * For all load averages >= 1 and max td_estcpu of 255, sleeping for at - * least six times the loadfactor will decay td_estcpu to zero. + * For all load averages >= 1 and max ts_estcpu of 255, sleeping for at + * least six times the loadfactor will decay ts_estcpu to zero. */ static void updatepri(struct thread *td) @@ -597,13 +599,13 @@ updatepri(struct thread *td) ts = td->td_sched; loadfac = loadfactor(averunnable.ldavg[0]); if (ts->ts_slptime > 5 * loadfac) - td->td_estcpu = 0; + ts->ts_estcpu = 0; else { - newcpu = td->td_estcpu; + newcpu = ts->ts_estcpu; ts->ts_slptime--; /* was incremented in schedcpu() */ while (newcpu && --ts->ts_slptime) newcpu = decay_cpu(loadfac, newcpu); - td->td_estcpu = newcpu; + ts->ts_estcpu = newcpu; } } @@ -615,15 +617,15 @@ updatepri(struct thread *td) static void resetpriority(struct thread *td) { - register unsigned int newpriority; + u_int newpriority; - if (td->td_pri_class == PRI_TIMESHARE) { - newpriority = PUSER + td->td_estcpu / INVERSE_ESTCPU_WEIGHT + - NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN); - newpriority = min(max(newpriority, PRI_MIN_TIMESHARE), - PRI_MAX_TIMESHARE); - sched_user_prio(td, newpriority); - } + if (td->td_pri_class != PRI_TIMESHARE) + return; + newpriority = PUSER + td->td_sched->ts_estcpu / INVERSE_ESTCPU_WEIGHT + + NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN); + newpriority = min(max(newpriority, PRI_MIN_TIMESHARE), + PRI_MAX_TIMESHARE); + sched_user_prio(td, newpriority); } /* @@ -709,18 +711,18 @@ sched_rr_interval(void) } /* - * We adjust the priority of the current process. The priority of - * a process gets worse as it accumulates CPU time. The cpu usage - * estimator (td_estcpu) is increased here. resetpriority() will - * compute a different priority each time td_estcpu increases by - * INVERSE_ESTCPU_WEIGHT - * (until MAXPRI is reached). The cpu usage estimator ramps up - * quite quickly when the process is running (linearly), and decays - * away exponentially, at a rate which is proportionally slower when - * the system is busy. The basic principle is that the system will - * 90% forget that the process used a lot of CPU time in 5 * loadav - * seconds. This causes the system to favor processes which haven't - * run much recently, and to round-robin among other processes. + * We adjust the priority of the current process. The priority of a + * process gets worse as it accumulates CPU time. The cpu usage + * estimator (ts_estcpu) is increased here. resetpriority() will + * compute a different priority each time ts_estcpu increases by + * INVERSE_ESTCPU_WEIGHT (until PRI_MAX_TIMESHARE is reached). The + * cpu usage estimator ramps up quite quickly when the process is + * running (linearly), and decays away exponentially, at a rate which + * is proportionally slower when the system is busy. The basic + * principle is that the system will 90% forget that the process used + * a lot of CPU time in 5 * loadav seconds. This causes the system to + * favor processes which haven't run much recently, and to round-robin + * among other processes. */ void sched_clock(struct thread *td) @@ -732,8 +734,8 @@ sched_clock(struct thread *td) ts = td->td_sched; ts->ts_cpticks++; - td->td_estcpu = ESTCPULIM(td->td_estcpu + 1); - if ((td->td_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) { + ts->ts_estcpu = ESTCPULIM(ts->ts_estcpu + 1); + if ((ts->ts_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) { resetpriority(td); resetpriority_thread(td); } @@ -773,7 +775,8 @@ sched_exit_thread(struct thread *td, str KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "exit", "prio:%d", child->td_priority); thread_lock(td); - td->td_estcpu = ESTCPULIM(td->td_estcpu + child->td_estcpu); + td->td_sched->ts_estcpu = ESTCPULIM(td->td_sched->ts_estcpu + + child->td_sched->ts_estcpu); thread_unlock(td); thread_lock(child); if ((child->td_flags & TDF_NOLOAD) == 0) @@ -794,12 +797,12 @@ sched_fork_thread(struct thread *td, str childtd->td_oncpu = NOCPU; childtd->td_lastcpu = NOCPU; - childtd->td_estcpu = td->td_estcpu; childtd->td_lock = &sched_lock; childtd->td_cpuset = cpuset_ref(td->td_cpuset); childtd->td_priority = childtd->td_base_pri; ts = childtd->td_sched; bzero(ts, sizeof(*ts)); + ts->ts_estcpu = td->td_sched->ts_estcpu; ts->ts_flags |= (td->td_sched->ts_flags & TSF_AFFINITY); ts->ts_slice = 1; } @@ -1621,9 +1624,11 @@ sched_pctcpu_delta(struct thread *td) } #endif -void -sched_tick(int cnt) +u_int +sched_estcpu(struct thread *td) { + + return (td->td_sched->ts_estcpu); } /* Modified: head/sys/kern/sched_ule.c ============================================================================== --- head/sys/kern/sched_ule.c Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/kern/sched_ule.c Sun Apr 17 11:04:27 2016 (r298145) @@ -2288,13 +2288,11 @@ sched_clock(struct thread *td) } } -/* - * Called once per hz tick. - */ -void -sched_tick(int cnt) +u_int +sched_estcpu(struct thread *td __unused) { + return (0); } /* Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/sys/proc.h Sun Apr 17 11:04:27 2016 (r298145) @@ -250,7 +250,6 @@ struct thread { int td_pinned; /* (k) Temporary cpu pin count. */ struct ucred *td_ucred; /* (k) Reference to credentials. */ struct plimit *td_limit; /* (k) Resource limits. */ - u_int td_estcpu; /* (t) estimated cpu utilization */ int td_slptick; /* (t) Time at sleep. */ int td_blktick; /* (t) Time spent blocked. */ int td_swvoltick; /* (t) Time at last SW_VOL switch. */ Modified: head/sys/sys/sched.h ============================================================================== --- head/sys/sys/sched.h Sun Apr 17 10:56:56 2016 (r298144) +++ head/sys/sys/sched.h Sun Apr 17 11:04:27 2016 (r298145) @@ -90,6 +90,7 @@ void sched_nice(struct proc *p, int nice * priorities inherited from their procs, and use up cpu time. */ void sched_exit_thread(struct thread *td, struct thread *child); +u_int sched_estcpu(struct thread *td); void sched_fork_thread(struct thread *td, struct thread *child); void sched_lend_prio(struct thread *td, u_char prio); void sched_lend_user_prio(struct thread *td, u_char pri); @@ -102,7 +103,6 @@ void sched_unlend_prio(struct thread *td void sched_user_prio(struct thread *td, u_char prio); void sched_userret(struct thread *td); void sched_wakeup(struct thread *td); -void sched_preempt(struct thread *td); #ifdef RACCT #ifdef SCHED_4BSD fixpt_t sched_pctcpu_delta(struct thread *td); @@ -114,8 +114,8 @@ fixpt_t sched_pctcpu_delta(struct thread */ void sched_add(struct thread *td, int flags); void sched_clock(struct thread *td); +void sched_preempt(struct thread *td); void sched_rem(struct thread *td); -void sched_tick(int cnt); void sched_relinquish(struct thread *td); struct thread *sched_choose(void); void sched_idletd(void *);
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