From 5bc19423a4c36efd168545afbc4198bf35c59b22 Mon Sep 17 00:00:00 2001 From: jhb Date: Tue, 3 Jan 2012 21:03:28 +0000 Subject: [PATCH 084/175] Some small fixes to CPU accounting for threads: - Only initialize the per-cpu switchticks and switchtime in sched_throw() for the very first context switch on APs during boot. This avoids a small gap between the middle of thread_exit() and sched_throw() where time is not accounted to any thread. - In thread_exit(), update the timestamp bookkeeping to track the changes to mi_switch() introduced by td_rux so that the code once again matches the comment claiming it is mimicing mi_switch(). Specifically, only update the per-thread stats directly and depend on ruxagg() to update p_rux rather than adjusting p_rux directly. While here, move the timestamp bookkeeping as late in the function as possible. Reviewed by: bde, kib MFC after: 1 week git-svn-id: http://svn.freebsd.org/base/head@229429 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f (cherry picked from commit a39711c607ef4eb7be2f2032bd58fe70ffbf733c) Signed-off-by: Xin Li --- sys/kern/kern_thread.c | 25 +++++++++++++++---------- sys/kern/sched_4bsd.c | 4 ++-- sys/kern/sched_ule.c | 4 ++-- 3 files changed, 19 insertions(+), 14 deletions(-) diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c index d9df5c3..d4c5c4c 100644 --- a/sys/kern/kern_thread.c +++ b/sys/kern/kern_thread.c @@ -381,7 +381,7 @@ thread_free(struct thread *td) void thread_exit(void) { - uint64_t new_switchtime; + uint64_t runtime, new_switchtime; struct thread *td; struct thread *td2; struct proc *p; @@ -410,15 +410,6 @@ thread_exit(void) */ cpu_thread_exit(td); /* XXXSMP */ - /* Do the same timestamp bookkeeping that mi_switch() would do. */ - new_switchtime = cpu_ticks(); - p->p_rux.rux_runtime += (new_switchtime - PCPU_GET(switchtime)); - PCPU_SET(switchtime, new_switchtime); - PCPU_SET(switchticks, ticks); - PCPU_INC(cnt.v_swtch); - /* Save our resource usage in our process. */ - td->td_ru.ru_nvcsw++; - rucollect(&p->p_ru, &td->td_ru); /* * The last thread is left attached to the process * So that the whole bundle gets recycled. Skip @@ -467,7 +458,21 @@ thread_exit(void) PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); #endif PROC_UNLOCK(p); + + /* Do the same timestamp bookkeeping that mi_switch() would do. */ + new_switchtime = cpu_ticks(); + runtime = new_switchtime - PCPU_GET(switchtime); + td->td_runtime += runtime; + td->td_incruntime += runtime; + PCPU_SET(switchtime, new_switchtime); + PCPU_SET(switchticks, ticks); + PCPU_INC(cnt.v_swtch); + + /* Save our resource usage in our process. */ + td->td_ru.ru_nvcsw++; ruxagg(p, td); + rucollect(&p->p_ru, &td->td_ru); + thread_lock(td); PROC_SUNLOCK(p); td->td_state = TDS_INACTIVE; diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c index 136080c..04fda5c 100644 --- a/sys/kern/sched_4bsd.c +++ b/sys/kern/sched_4bsd.c @@ -1571,14 +1571,14 @@ sched_throw(struct thread *td) if (td == NULL) { mtx_lock_spin(&sched_lock); spinlock_exit(); + PCPU_SET(switchtime, cpu_ticks()); + PCPU_SET(switchticks, ticks); } else { lock_profile_release_lock(&sched_lock.lock_object); MPASS(td->td_lock == &sched_lock); } mtx_assert(&sched_lock, MA_OWNED); KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count")); - PCPU_SET(switchtime, cpu_ticks()); - PCPU_SET(switchticks, ticks); cpu_throw(td, choosethread()); /* doesn't return */ } diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c index 87e3655..2065b9f 100644 --- a/sys/kern/sched_ule.c +++ b/sys/kern/sched_ule.c @@ -2587,6 +2587,8 @@ sched_throw(struct thread *td) /* Correct spinlock nesting and acquire the correct lock. */ TDQ_LOCK(tdq); spinlock_exit(); + PCPU_SET(switchtime, cpu_ticks()); + PCPU_SET(switchticks, ticks); } else { MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); tdq_load_rem(tdq, td); @@ -2595,8 +2597,6 @@ sched_throw(struct thread *td) KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count")); newtd = choosethread(); TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd; - PCPU_SET(switchtime, cpu_ticks()); - PCPU_SET(switchticks, ticks); cpu_throw(td, newtd); /* doesn't return */ } -- 1.7.9.4