From ef5f88c3578682534931b6958f99bdc1a6a33869 Mon Sep 17 00:00:00 2001 From: kib Date: Sun, 5 Jun 2016 17:04:03 +0000 Subject: Get rid of struct proc p_sched and struct thread td_sched pointers. p_sched is unused. The struct td_sched is always co-allocated with the struct thread, except for the thread0. Avoid useless indirection, instead calculate td_sched location using simple pointer arithmetic in td_get_sched(9). For thread0, which is statically allocated, create a structure to emulate layout of the dynamic allocation. Reviewed by: jhb (previous version) Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D6711 --- sys/kern/sched_4bsd.c | 60 +++++++++++++++++++++++++++------------------------ 1 file changed, 32 insertions(+), 28 deletions(-) (limited to 'sys/kern/sched_4bsd.c') diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c index 25afe98..7de56b6 100644 --- a/sys/kern/sched_4bsd.c +++ b/sys/kern/sched_4bsd.c @@ -117,7 +117,10 @@ struct td_sched { #define THREAD_CAN_SCHED(td, cpu) \ CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask) -static struct td_sched td_sched0; +_Static_assert(sizeof(struct thread) + sizeof(struct td_sched) <= + sizeof(struct thread0_storage), + "increase struct thread0_storage.t0st_sched size"); + static struct mtx sched_lock; static int realstathz = 127; /* stathz is sometimes 0 and run off of hz. */ @@ -491,8 +494,8 @@ schedcpu(void) } FOREACH_THREAD_IN_PROC(p, td) { awake = 0; + ts = td_get_sched(td); thread_lock(td); - ts = td->td_sched; /* * Increment sleep time (if sleeping). We * ignore overflow, as above. @@ -596,7 +599,7 @@ updatepri(struct thread *td) fixpt_t loadfac; unsigned int newcpu; - ts = td->td_sched; + ts = td_get_sched(td); loadfac = loadfactor(averunnable.ldavg[0]); if (ts->ts_slptime > 5 * loadfac) ts->ts_estcpu = 0; @@ -621,7 +624,8 @@ resetpriority(struct thread *td) if (td->td_pri_class != PRI_TIMESHARE) return; - newpriority = PUSER + td->td_sched->ts_estcpu / INVERSE_ESTCPU_WEIGHT + + newpriority = PUSER + + td_get_sched(td)->ts_estcpu / INVERSE_ESTCPU_WEIGHT + NICE_WEIGHT * (td->td_proc->p_nice - PRIO_MIN); newpriority = min(max(newpriority, PRI_MIN_TIMESHARE), PRI_MAX_TIMESHARE); @@ -682,13 +686,12 @@ sched_initticks(void *dummy) void schedinit(void) { + /* - * Set up the scheduler specific parts of proc0. + * Set up the scheduler specific parts of thread0. */ - proc0.p_sched = NULL; /* XXX */ - thread0.td_sched = &td_sched0; thread0.td_lock = &sched_lock; - td_sched0.ts_slice = sched_slice; + td_get_sched(&thread0)->ts_slice = sched_slice; mtx_init(&sched_lock, "sched lock", NULL, MTX_SPIN | MTX_RECURSE); } @@ -731,7 +734,7 @@ sched_clock(struct thread *td) struct td_sched *ts; THREAD_LOCK_ASSERT(td, MA_OWNED); - ts = td->td_sched; + ts = td_get_sched(td); ts->ts_cpticks++; ts->ts_estcpu = ESTCPULIM(ts->ts_estcpu + 1); @@ -775,8 +778,8 @@ sched_exit_thread(struct thread *td, struct thread *child) KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "exit", "prio:%d", child->td_priority); thread_lock(td); - td->td_sched->ts_estcpu = ESTCPULIM(td->td_sched->ts_estcpu + - child->td_sched->ts_estcpu); + td_get_sched(td)->ts_estcpu = ESTCPULIM(td_get_sched(td)->ts_estcpu + + td_get_sched(child)->ts_estcpu); thread_unlock(td); thread_lock(child); if ((child->td_flags & TDF_NOLOAD) == 0) @@ -793,17 +796,18 @@ sched_fork(struct thread *td, struct thread *childtd) void sched_fork_thread(struct thread *td, struct thread *childtd) { - struct td_sched *ts; + struct td_sched *ts, *tsc; childtd->td_oncpu = NOCPU; childtd->td_lastcpu = NOCPU; childtd->td_lock = &sched_lock; childtd->td_cpuset = cpuset_ref(td->td_cpuset); childtd->td_priority = childtd->td_base_pri; - ts = childtd->td_sched; + ts = td_get_sched(childtd); bzero(ts, sizeof(*ts)); - ts->ts_estcpu = td->td_sched->ts_estcpu; - ts->ts_flags |= (td->td_sched->ts_flags & TSF_AFFINITY); + tsc = td_get_sched(td); + ts->ts_estcpu = tsc->ts_estcpu; + ts->ts_flags |= (tsc->ts_flags & TSF_AFFINITY); ts->ts_slice = 1; } @@ -952,7 +956,7 @@ sched_sleep(struct thread *td, int pri) THREAD_LOCK_ASSERT(td, MA_OWNED); td->td_slptick = ticks; - td->td_sched->ts_slptime = 0; + td_get_sched(td)->ts_slptime = 0; if (pri != 0 && PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) sched_prio(td, pri); if (TD_IS_SUSPENDED(td) || pri >= PSOCK) @@ -968,7 +972,7 @@ sched_switch(struct thread *td, struct thread *newtd, int flags) int preempted; tmtx = NULL; - ts = td->td_sched; + ts = td_get_sched(td); p = td->td_proc; THREAD_LOCK_ASSERT(td, MA_OWNED); @@ -1095,7 +1099,7 @@ sched_wakeup(struct thread *td) struct td_sched *ts; THREAD_LOCK_ASSERT(td, MA_OWNED); - ts = td->td_sched; + ts = td_get_sched(td); td->td_flags &= ~TDF_CANSWAP; if (ts->ts_slptime > 1) { updatepri(td); @@ -1266,7 +1270,7 @@ sched_add(struct thread *td, int flags) int forwarded = 0; int single_cpu = 0; - ts = td->td_sched; + ts = td_get_sched(td); THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT((td->td_inhibitors == 0), ("sched_add: trying to run inhibited thread")); @@ -1361,7 +1365,7 @@ sched_add(struct thread *td, int flags) { struct td_sched *ts; - ts = td->td_sched; + ts = td_get_sched(td); THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT((td->td_inhibitors == 0), ("sched_add: trying to run inhibited thread")); @@ -1414,7 +1418,7 @@ sched_rem(struct thread *td) { struct td_sched *ts; - ts = td->td_sched; + ts = td_get_sched(td); KASSERT(td->td_flags & TDF_INMEM, ("sched_rem: thread swapped out")); KASSERT(TD_ON_RUNQ(td), @@ -1527,7 +1531,7 @@ sched_bind(struct thread *td, int cpu) THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED); KASSERT(td == curthread, ("sched_bind: can only bind curthread")); - ts = td->td_sched; + ts = td_get_sched(td); td->td_flags |= TDF_BOUND; #ifdef SMP @@ -1586,7 +1590,7 @@ sched_pctcpu(struct thread *td) struct td_sched *ts; THREAD_LOCK_ASSERT(td, MA_OWNED); - ts = td->td_sched; + ts = td_get_sched(td); return (ts->ts_pctcpu); } @@ -1603,7 +1607,7 @@ sched_pctcpu_delta(struct thread *td) int realstathz; THREAD_LOCK_ASSERT(td, MA_OWNED); - ts = td->td_sched; + ts = td_get_sched(td); delta = 0; realstathz = stathz ? stathz : hz; if (ts->ts_cpticks != 0) { @@ -1628,7 +1632,7 @@ u_int sched_estcpu(struct thread *td) { - return (td->td_sched->ts_estcpu); + return (td_get_sched(td)->ts_estcpu); } /* @@ -1707,7 +1711,7 @@ sched_tdname(struct thread *td) #ifdef KTR struct td_sched *ts; - ts = td->td_sched; + ts = td_get_sched(td); if (ts->ts_name[0] == '\0') snprintf(ts->ts_name, sizeof(ts->ts_name), "%s tid %d", td->td_name, td->td_tid); @@ -1723,7 +1727,7 @@ sched_clear_tdname(struct thread *td) { struct td_sched *ts; - ts = td->td_sched; + ts = td_get_sched(td); ts->ts_name[0] = '\0'; } #endif @@ -1741,7 +1745,7 @@ sched_affinity(struct thread *td) * Set the TSF_AFFINITY flag if there is at least one CPU this * thread can't run on. */ - ts = td->td_sched; + ts = td_get_sched(td); ts->ts_flags &= ~TSF_AFFINITY; CPU_FOREACH(cpu) { if (!THREAD_CAN_SCHED(td, cpu)) { -- cgit v1.1