Date: Thu, 10 May 2012 10:16:22 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r235221 - stable/9/sys/kern Message-ID: <201205101016.q4AAGMAu028204@svn.freebsd.org>
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Author: kib Date: Thu May 10 10:16:21 2012 New Revision: 235221 URL: http://svn.freebsd.org/changeset/base/235221 Log: MFC r234981: Move the code to call the callout callback into the helper function softclock_call_cc(). While there, move some common code to callout_cc_del(). Modified: stable/9/sys/kern/kern_timeout.c Directory Properties: stable/9/sys/ (props changed) Modified: stable/9/sys/kern/kern_timeout.c ============================================================================== --- stable/9/sys/kern/kern_timeout.c Thu May 10 10:02:56 2012 (r235220) +++ stable/9/sys/kern/kern_timeout.c Thu May 10 10:16:21 2012 (r235221) @@ -437,6 +437,181 @@ callout_cc_add(struct callout *c, struct } } +static void +callout_cc_del(struct callout *c, struct callout_cpu *cc) +{ + + if (cc->cc_next == c) + cc->cc_next = TAILQ_NEXT(c, c_links.tqe); + if (c->c_flags & CALLOUT_LOCAL_ALLOC) { + c->c_func = NULL; + SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle); + } +} + +static struct callout * +softclock_call_cc(struct callout *c, struct callout_cpu *cc, int *mpcalls, + int *lockcalls, int *gcalls) +{ + void (*c_func)(void *); + void *c_arg; + struct lock_class *class; + struct lock_object *c_lock; + int c_flags, sharedlock; +#ifdef SMP + struct callout_cpu *new_cc; + void (*new_func)(void *); + void *new_arg; + int new_cpu, new_ticks; +#endif +#ifdef DIAGNOSTIC + struct bintime bt1, bt2; + struct timespec ts2; + static uint64_t maxdt = 36893488147419102LL; /* 2 msec */ + static timeout_t *lastfunc; +#endif + + cc->cc_next = TAILQ_NEXT(c, c_links.tqe); + class = (c->c_lock != NULL) ? LOCK_CLASS(c->c_lock) : NULL; + sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ? 0 : 1; + c_lock = c->c_lock; + c_func = c->c_func; + c_arg = c->c_arg; + c_flags = c->c_flags; + if (c->c_flags & CALLOUT_LOCAL_ALLOC) + c->c_flags = CALLOUT_LOCAL_ALLOC; + else + c->c_flags &= ~CALLOUT_PENDING; + cc->cc_curr = c; + cc->cc_cancel = 0; + CC_UNLOCK(cc); + if (c_lock != NULL) { + class->lc_lock(c_lock, sharedlock); + /* + * The callout may have been cancelled + * while we switched locks. + */ + if (cc->cc_cancel) { + class->lc_unlock(c_lock); + goto skip; + } + /* The callout cannot be stopped now. */ + cc->cc_cancel = 1; + + if (c_lock == &Giant.lock_object) { + (*gcalls)++; + CTR3(KTR_CALLOUT, "callout %p func %p arg %p", + c, c_func, c_arg); + } else { + (*lockcalls)++; + CTR3(KTR_CALLOUT, "callout lock %p func %p arg %p", + c, c_func, c_arg); + } + } else { + (*mpcalls)++; + CTR3(KTR_CALLOUT, "callout mpsafe %p func %p arg %p", + c, c_func, c_arg); + } +#ifdef DIAGNOSTIC + binuptime(&bt1); +#endif + THREAD_NO_SLEEPING(); + SDT_PROBE(callout_execute, kernel, , callout_start, c, 0, 0, 0, 0); + c_func(c_arg); + SDT_PROBE(callout_execute, kernel, , callout_end, c, 0, 0, 0, 0); + THREAD_SLEEPING_OK(); +#ifdef DIAGNOSTIC + binuptime(&bt2); + bintime_sub(&bt2, &bt1); + if (bt2.frac > maxdt) { + if (lastfunc != c_func || bt2.frac > maxdt * 2) { + bintime2timespec(&bt2, &ts2); + printf( + "Expensive timeout(9) function: %p(%p) %jd.%09ld s\n", + c_func, c_arg, (intmax_t)ts2.tv_sec, ts2.tv_nsec); + } + maxdt = bt2.frac; + lastfunc = c_func; + } +#endif + CTR1(KTR_CALLOUT, "callout %p finished", c); + if ((c_flags & CALLOUT_RETURNUNLOCKED) == 0) + class->lc_unlock(c_lock); +skip: + CC_LOCK(cc); + /* + * If the current callout is locally allocated (from + * timeout(9)) then put it on the freelist. + * + * Note: we need to check the cached copy of c_flags because + * if it was not local, then it's not safe to deref the + * callout pointer. + */ + if (c_flags & CALLOUT_LOCAL_ALLOC) { + KASSERT(c->c_flags == CALLOUT_LOCAL_ALLOC, + ("corrupted callout")); + c->c_func = NULL; + SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle); + } + cc->cc_curr = NULL; + if (cc->cc_waiting) { + /* + * There is someone waiting for the + * callout to complete. + * If the callout was scheduled for + * migration just cancel it. + */ + if (cc_cme_migrating(cc)) + cc_cme_cleanup(cc); + cc->cc_waiting = 0; + CC_UNLOCK(cc); + wakeup(&cc->cc_waiting); + CC_LOCK(cc); + } else if (cc_cme_migrating(cc)) { +#ifdef SMP + /* + * If the callout was scheduled for + * migration just perform it now. + */ + new_cpu = cc->cc_migration_cpu; + new_ticks = cc->cc_migration_ticks; + new_func = cc->cc_migration_func; + new_arg = cc->cc_migration_arg; + cc_cme_cleanup(cc); + + /* + * Handle deferred callout stops + */ + if ((c->c_flags & CALLOUT_DFRMIGRATION) == 0) { + CTR3(KTR_CALLOUT, + "deferred cancelled %p func %p arg %p", + c, new_func, new_arg); + callout_cc_del(c, cc); + goto nextc; + } + + c->c_flags &= ~CALLOUT_DFRMIGRATION; + + /* + * It should be assert here that the + * callout is not destroyed but that + * is not easy. + */ + new_cc = callout_cpu_switch(c, cc, new_cpu); + callout_cc_add(c, new_cc, new_ticks, new_func, new_arg, + new_cpu); + CC_UNLOCK(new_cc); + CC_LOCK(cc); +#else + panic("migration should not happen"); +#endif + } +#ifdef SMP +nextc: +#endif + return (cc->cc_next); +} + /* * The callout mechanism is based on the work of Adam M. Costello and * George Varghese, published in a technical report entitled "Redesigning @@ -465,12 +640,6 @@ softclock(void *arg) int mpcalls; int lockcalls; int gcalls; -#ifdef DIAGNOSTIC - struct bintime bt1, bt2; - struct timespec ts2; - static uint64_t maxdt = 36893488147419102LL; /* 2 msec */ - static timeout_t *lastfunc; -#endif #ifndef MAX_SOFTCLOCK_STEPS #define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */ @@ -492,7 +661,7 @@ softclock(void *arg) cc->cc_softticks++; bucket = &cc->cc_callwheel[curticks & callwheelmask]; c = TAILQ_FIRST(bucket); - while (c) { + while (c != NULL) { depth++; if (c->c_time != curticks) { c = TAILQ_NEXT(c, c_links.tqe); @@ -507,189 +676,10 @@ softclock(void *arg) steps = 0; } } else { - void (*c_func)(void *); - void *c_arg; - struct lock_class *class; - struct lock_object *c_lock; - int c_flags, sharedlock; - - cc->cc_next = TAILQ_NEXT(c, c_links.tqe); TAILQ_REMOVE(bucket, c, c_links.tqe); - class = (c->c_lock != NULL) ? - LOCK_CLASS(c->c_lock) : NULL; - sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ? - 0 : 1; - c_lock = c->c_lock; - c_func = c->c_func; - c_arg = c->c_arg; - c_flags = c->c_flags; - if (c->c_flags & CALLOUT_LOCAL_ALLOC) { - c->c_flags = CALLOUT_LOCAL_ALLOC; - } else { - c->c_flags = - (c->c_flags & ~CALLOUT_PENDING); - } - cc->cc_curr = c; - cc->cc_cancel = 0; - CC_UNLOCK(cc); - if (c_lock != NULL) { - class->lc_lock(c_lock, sharedlock); - /* - * The callout may have been cancelled - * while we switched locks. - */ - if (cc->cc_cancel) { - class->lc_unlock(c_lock); - goto skip; - } - /* The callout cannot be stopped now. */ - cc->cc_cancel = 1; - - if (c_lock == &Giant.lock_object) { - gcalls++; - CTR3(KTR_CALLOUT, - "callout %p func %p arg %p", - c, c_func, c_arg); - } else { - lockcalls++; - CTR3(KTR_CALLOUT, "callout lock" - " %p func %p arg %p", - c, c_func, c_arg); - } - } else { - mpcalls++; - CTR3(KTR_CALLOUT, - "callout mpsafe %p func %p arg %p", - c, c_func, c_arg); - } -#ifdef DIAGNOSTIC - binuptime(&bt1); -#endif - THREAD_NO_SLEEPING(); - SDT_PROBE(callout_execute, kernel, , - callout_start, c, 0, 0, 0, 0); - c_func(c_arg); - SDT_PROBE(callout_execute, kernel, , - callout_end, c, 0, 0, 0, 0); - THREAD_SLEEPING_OK(); -#ifdef DIAGNOSTIC - binuptime(&bt2); - bintime_sub(&bt2, &bt1); - if (bt2.frac > maxdt) { - if (lastfunc != c_func || - bt2.frac > maxdt * 2) { - bintime2timespec(&bt2, &ts2); - printf( - "Expensive timeout(9) function: %p(%p) %jd.%09ld s\n", - c_func, c_arg, - (intmax_t)ts2.tv_sec, - ts2.tv_nsec); - } - maxdt = bt2.frac; - lastfunc = c_func; - } -#endif - CTR1(KTR_CALLOUT, "callout %p finished", c); - if ((c_flags & CALLOUT_RETURNUNLOCKED) == 0) - class->lc_unlock(c_lock); - skip: - CC_LOCK(cc); - /* - * If the current callout is locally - * allocated (from timeout(9)) - * then put it on the freelist. - * - * Note: we need to check the cached - * copy of c_flags because if it was not - * local, then it's not safe to deref the - * callout pointer. - */ - if (c_flags & CALLOUT_LOCAL_ALLOC) { - KASSERT(c->c_flags == - CALLOUT_LOCAL_ALLOC, - ("corrupted callout")); - c->c_func = NULL; - SLIST_INSERT_HEAD(&cc->cc_callfree, c, - c_links.sle); - } - cc->cc_curr = NULL; - if (cc->cc_waiting) { - - /* - * There is someone waiting for the - * callout to complete. - * If the callout was scheduled for - * migration just cancel it. - */ - if (cc_cme_migrating(cc)) - cc_cme_cleanup(cc); - cc->cc_waiting = 0; - CC_UNLOCK(cc); - wakeup(&cc->cc_waiting); - CC_LOCK(cc); - } else if (cc_cme_migrating(cc)) { -#ifdef SMP - struct callout_cpu *new_cc; - void (*new_func)(void *); - void *new_arg; - int new_cpu, new_ticks; - - /* - * If the callout was scheduled for - * migration just perform it now. - */ - new_cpu = cc->cc_migration_cpu; - new_ticks = cc->cc_migration_ticks; - new_func = cc->cc_migration_func; - new_arg = cc->cc_migration_arg; - cc_cme_cleanup(cc); - - /* - * Handle deferred callout stops - */ - if ((c->c_flags & CALLOUT_DFRMIGRATION) - == 0) { - CTR3(KTR_CALLOUT, - "deferred cancelled %p func %p arg %p", - c, new_func, new_arg); - if (cc->cc_next == c) { - cc->cc_next = - TAILQ_NEXT(c, - c_links.tqe); - } - if (c->c_flags & - CALLOUT_LOCAL_ALLOC) { - c->c_func = NULL; - SLIST_INSERT_HEAD( - &cc->cc_callfree, c, - c_links.sle); - } - goto nextc; - } else { - c->c_flags &= ~ - CALLOUT_DFRMIGRATION; - } - - /* - * It should be assert here that the - * callout is not destroyed but that - * is not easy. - */ - new_cc = callout_cpu_switch(c, cc, - new_cpu); - callout_cc_add(c, new_cc, new_ticks, - new_func, new_arg, new_cpu); - CC_UNLOCK(new_cc); - CC_LOCK(cc); -#else - panic("migration should not happen"); -#endif - } -#ifdef SMP -nextc: -#endif + c = softclock_call_cc(c, cc, &mpcalls, + &lockcalls, &gcalls); steps = 0; - c = cc->cc_next; } } } @@ -1032,19 +1022,12 @@ again: c->c_flags &= ~(CALLOUT_ACTIVE | CALLOUT_PENDING); - if (cc->cc_next == c) { - cc->cc_next = TAILQ_NEXT(c, c_links.tqe); - } - TAILQ_REMOVE(&cc->cc_callwheel[c->c_time & callwheelmask], c, - c_links.tqe); - CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p", c, c->c_func, c->c_arg); + TAILQ_REMOVE(&cc->cc_callwheel[c->c_time & callwheelmask], c, + c_links.tqe); + callout_cc_del(c, cc); - if (c->c_flags & CALLOUT_LOCAL_ALLOC) { - c->c_func = NULL; - SLIST_INSERT_HEAD(&cc->cc_callfree, c, c_links.sle); - } CC_UNLOCK(cc); return (1); }
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