From b3140862f54f556a07bb57298f0327c9b95770fa Mon Sep 17 00:00:00 2001 From: tegge Date: Thu, 22 Feb 2001 19:50:37 +0000 Subject: Protect update of the per processor switchtime variable against interrupts. Protect usage of the per processor switchtime variable against interrupts in calcru(). This seem to eliminate the "microuptime() went backwards" warnings. --- sys/kern/kern_exit.c | 6 +++++- sys/kern/kern_resource.c | 20 ++++++++++++++------ 2 files changed, 19 insertions(+), 7 deletions(-) (limited to 'sys') diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c index 440ee3a..08cbb28 100644 --- a/sys/kern/kern_exit.c +++ b/sys/kern/kern_exit.c @@ -118,6 +118,7 @@ exit1(p, rv) register struct proc *q, *nq; register struct vmspace *vm; struct exitlist *ep; + struct timeval new_switchtime; if (p->p_pid == 1) { printf("init died (signal %d, exit %d)\n", @@ -325,7 +326,10 @@ exit1(p, rv) * directly. Set it now so that the rest of the exit time gets * counted somewhere if possible. */ - microuptime(PCPU_PTR(switchtime)); + mtx_lock_spin(&sched_lock); + microuptime(&new_switchtime); + PCPU_SET(switchtime, new_switchtime); + mtx_unlock_spin(&sched_lock); PCPU_SET(switchticks, ticks); /* diff --git a/sys/kern/kern_resource.c b/sys/kern/kern_resource.c index 73ffb03..b872acd 100644 --- a/sys/kern/kern_resource.c +++ b/sys/kern/kern_resource.c @@ -567,19 +567,27 @@ calcru(p, up, sp, ip) tu = p->p_runtime; if (p == curproc) { + struct timeval old_switchtime; /* * Adjust for the current time slice. This is actually fairly * important since the error here is on the order of a time * quantum, which is much greater than the sampling error. */ - microuptime(&tv); - if (timevalcmp(&tv, PCPU_PTR(switchtime), <)) + do { + old_switchtime = PCPU_GET(switchtime); + microuptime(&tv); + } while (old_switchtime.tv_sec != + PCPU_GET(switchtime.tv_sec) || + old_switchtime.tv_usec != + PCPU_GET(switchtime.tv_usec)); + if (timevalcmp(&tv, &old_switchtime, <)) printf("microuptime() went backwards (%ld.%06ld -> %ld.%06ld)\n", - PCPU_GET(switchtime.tv_sec), PCPU_GET(switchtime.tv_usec), - tv.tv_sec, tv.tv_usec); + old_switchtime.tv_sec, + old_switchtime.tv_usec, + tv.tv_sec, tv.tv_usec); else - tu += (tv.tv_usec - PCPU_GET(switchtime.tv_usec)) + - (tv.tv_sec - PCPU_GET(switchtime.tv_sec)) * + tu += (tv.tv_usec - old_switchtime.tv_usec) + + (tv.tv_sec - old_switchtime.tv_sec) * (int64_t)1000000; } ptu = p->p_uu + p->p_su + p->p_iu; -- cgit v1.1