diff options
author | davidxu <davidxu@FreeBSD.org> | 2003-03-19 05:49:38 +0000 |
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committer | davidxu <davidxu@FreeBSD.org> | 2003-03-19 05:49:38 +0000 |
commit | 8e88e8da057497b66069752a6391f435c706b441 (patch) | |
tree | 8bb70eacef4e1a4571ae518b0ff0001588c0db1b /sys/kern/kern_thread.c | |
parent | 6564ae81018f9caddd72fe4b8f51c200cad0bd78 (diff) | |
download | FreeBSD-src-8e88e8da057497b66069752a6391f435c706b441.zip FreeBSD-src-8e88e8da057497b66069752a6391f435c706b441.tar.gz |
Adjust code for userland preemptive. Userland can set a quantum in
kse_mailbox to schedule an upcall, this is useful for userland timeout
routine, for example pthread_cond_timedwait().
Also extract upcall scheduling code from kse_reassign and create
a new function called thread_switchout to include these code.
Reviewed by: julain
Diffstat (limited to 'sys/kern/kern_thread.c')
-rw-r--r-- | sys/kern/kern_thread.c | 69 |
1 files changed, 45 insertions, 24 deletions
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c index 81b0ed5..9456646 100644 --- a/sys/kern/kern_thread.c +++ b/sys/kern/kern_thread.c @@ -696,6 +696,8 @@ kse_create(struct thread *td, struct kse_create_args *uap) return (EPROCLIM); } upcall_link(newku, newkg); + if (mbx.km_quantum) + newkg->kg_upquantum = max(1, mbx.km_quantum/tick); /* * Each upcall structure has an owner thread, find which @@ -1002,11 +1004,6 @@ thread_export_context(struct thread *td) if (suword(addr, temp)) goto bad; - addr = (caddr_t)(&td->td_mailbox->tm_slices); - temp = fuword(addr) - td->td_usticks; - if (suword(addr, temp)) - goto bad; - /* Get address in latest mbox of list pointer */ addr = (void *)(&td->td_mailbox->tm_next); /* @@ -1118,9 +1115,9 @@ thread_update_usr_ticks(struct thread *td, int user) struct proc *p = td->td_proc; struct kse_thr_mailbox *tmbx; struct kse_upcall *ku; + struct ksegrp *kg; caddr_t addr; uint uticks; - int slices; if ((ku = td->td_upcall) == NULL) return (-1); @@ -1144,22 +1141,12 @@ thread_update_usr_ticks(struct thread *td, int user) PROC_UNLOCK(p); return (-2); } - addr = (caddr_t)&tmbx->tm_slices; - slices = (int)fuword(addr); - if (slices > 0) { - slices -= (int)uticks; - if (suword(addr, slices)) { - PROC_LOCK(p); - psignal(p, SIGSEGV); - PROC_UNLOCK(p); - return (-2); - } - if (slices <= 0) { - mtx_lock_spin(&sched_lock); - td->td_upcall->ku_flags |= KUF_DOUPCALL; - mtx_unlock_spin(&sched_lock); - } - } + } + kg = td->td_ksegrp; + if (kg->kg_upquantum && ticks >= kg->kg_nextupcall) { + mtx_lock_spin(&sched_lock); + td->td_upcall->ku_flags |= KUF_DOUPCALL; + mtx_unlock_spin(&sched_lock); } return (0); } @@ -1496,6 +1483,38 @@ thread_signal_upcall(struct thread *td) return; } +void +thread_switchout(struct thread *td) +{ + struct kse_upcall *ku; + + mtx_assert(&sched_lock, MA_OWNED); + + /* + * If the outgoing thread is in threaded group and has never + * scheduled an upcall, decide whether this is a short + * or long term event and thus whether or not to schedule + * an upcall. + * If it is a short term event, just suspend it in + * a way that takes its KSE with it. + * Select the events for which we want to schedule upcalls. + * For now it's just sleep. + * XXXKSE eventually almost any inhibition could do. + */ + if (TD_CAN_UNBIND(td) && (td->td_standin) && TD_ON_SLEEPQ(td)) { + /* + * Release ownership of upcall, and schedule an upcall + * thread, this new upcall thread becomes the owner of + * the upcall structure. + */ + ku = td->td_upcall; + ku->ku_owner = NULL; + td->td_upcall = NULL; + td->td_flags &= ~TDF_CAN_UNBIND; + thread_schedule_upcall(td, ku); + } +} + /* * Setup done on the thread when it enters the kernel. * XXXKSE Presently only for syscalls but eventually all kernel entries. @@ -1606,10 +1625,11 @@ thread_userret(struct thread *td, struct trapframe *frame) ku = td->td_upcall; if ((p->p_flag & PS_NEEDSIGCHK) == 0 && (kg->kg_completed == NULL) && - (ku->ku_flags & KUF_DOUPCALL) == 0) { + (ku->ku_flags & KUF_DOUPCALL) == 0 && + (kg->kg_upquantum && ticks >= kg->kg_nextupcall)) { thread_update_usr_ticks(td, 0); nanotime(&ts); - error = copyout(&ts, + error = copyout(&ts, (caddr_t)&ku->ku_mailbox->km_timeofday, sizeof(ts)); td->td_mailbox = 0; @@ -1679,6 +1699,7 @@ thread_userret(struct thread *td, struct trapframe *frame) } if (td->td_flags & TDF_UPCALLING) { + kg->kg_nextupcall = ticks+kg->kg_upquantum; ku = td->td_upcall; /* * There is no more work to do and we are going to ride |