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author | Mateusz Guzik <mjg@FreeBSD.org> | 2017-11-17 02:45:38 +0000 |
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committer | Mateusz Guzik <mjg@FreeBSD.org> | 2017-11-17 02:45:38 +0000 |
commit | 32aef9ff05d6dda84bd8924efca2f5fb30e602d2 (patch) | |
tree | 84cecf385e7c6ef1f57ec0a68b266bef7ab73fcb /sys | |
parent | 997131646f75f696f4fd2e066896da7f552f87eb (diff) | |
download | src-32aef9ff05d6dda84bd8924efca2f5fb30e602d2.tar.gz src-32aef9ff05d6dda84bd8924efca2f5fb30e602d2.zip |
sched: move panic handling code out of choosethread
This avoids jumps in the common case of the kernel not being panicked.
Notes
Notes:
svn path=/head/; revision=325924
Diffstat (limited to 'sys')
-rw-r--r-- | sys/kern/kern_switch.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c index f58acd5ed4c6..2cdec8d930f9 100644 --- a/sys/kern/kern_switch.c +++ b/sys/kern/kern_switch.c @@ -150,22 +150,21 @@ SYSCTL_PROC(_kern_sched_stats, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_WR, NULL, /* * Select the thread that will be run next. */ -struct thread * -choosethread(void) -{ - struct thread *td; -retry: - td = sched_choose(); +static __noinline struct thread * +choosethread_panic(struct thread *td) +{ /* * If we are in panic, only allow system threads, * plus the one we are running in, to be run. */ - if (panicstr && ((td->td_proc->p_flag & P_SYSTEM) == 0 && +retry: + if (((td->td_proc->p_flag & P_SYSTEM) == 0 && (td->td_flags & TDF_INPANIC) == 0)) { /* note that it is no longer on the run queue */ TD_SET_CAN_RUN(td); + td = sched_choose(); goto retry; } @@ -173,6 +172,20 @@ retry: return (td); } +struct thread * +choosethread(void) +{ + struct thread *td; + + td = sched_choose(); + + if (__predict_false(panicstr != NULL)) + return (choosethread_panic(td)); + + TD_SET_RUNNING(td); + return (td); +} + /* * Kernel thread preemption implementation. Critical sections mark * regions of code in which preemptions are not allowed. |