diff options
Diffstat (limited to 'usr/src/uts/common/os/cyclic.c')
| -rw-r--r-- | usr/src/uts/common/os/cyclic.c | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/usr/src/uts/common/os/cyclic.c b/usr/src/uts/common/os/cyclic.c index 21907b4957..45e13ebeab 100644 --- a/usr/src/uts/common/os/cyclic.c +++ b/usr/src/uts/common/os/cyclic.c @@ -24,7 +24,7 @@ */ /* - * Copyright (c) 2012, Joyent Inc. All rights reserved. + * Copyright 2018 Joyent Inc. */ /* @@ -112,6 +112,7 @@ * cyclic_remove() <-- Removes a cyclic * cyclic_bind() <-- Change a cyclic's CPU or partition binding * cyclic_reprogram() <-- Reprogram a cyclic's expiration + * cyclic_move_here() <-- Shuffle cyclic to current CPU * * Inter-subsystem Interfaces * @@ -3111,6 +3112,61 @@ cyclic_reprogram(cyclic_id_t id, hrtime_t expiration) return (1); } +/* + * void cyclic_move_here(cyclic_id_t) + * + * Overview + * + * cyclic_move_here() attempts to shuffle a cyclic onto the current CPU. + * + * Arguments and notes + * + * The first argument is a cyclic_id returned from cyclic_add(). + * cyclic_move_here() may _not_ be called on a cyclic_id returned from + * cyclic_add_omni() or one bound to a CPU or partition via cyclic_bind(). + * + * This cyclic shuffling is performed on a best-effort basis. If for some + * reason the current CPU is unsuitable or the thread migrates between CPUs + * during the call, the function may return with the cyclic residing on some + * other CPU. + * + * Return value + * + * None; cyclic_move_here() always reports success. + * + * Caller's context + * + * cpu_lock must be held by the caller, and the caller must not be in + * interrupt context. The caller may not hold any locks which are also + * grabbed by any cyclic handler. + */ +void +cyclic_move_here(cyclic_id_t id) +{ + cyc_id_t *idp = (cyc_id_t *)id; + cyc_cpu_t *cc = idp->cyi_cpu; + cpu_t *dest = CPU; + + ASSERT(MUTEX_HELD(&cpu_lock)); + CYC_PTRACE("move_here", idp, dest); + VERIFY3P(cc, !=, NULL); + VERIFY3U(cc->cyp_cyclics[idp->cyi_ndx].cy_flags & + (CYF_CPU_BOUND|CYF_PART_BOUND), ==, 0); + + if (cc->cyp_cpu == dest) { + return; + } + + /* Is the destination CPU suitable for a migration target? */ + if (dest->cpu_cyclic == NULL || + dest->cpu_cyclic->cyp_state == CYS_OFFLINE || + (dest->cpu_flags & CPU_ENABLE) == 0) { + return; + } + + cyclic_juggle_one_to(idp, dest->cpu_cyclic); +} + hrtime_t cyclic_getres() { |