git: c7aa0304d5b5 - main - Run softclock threads at a hardware ithread priority.

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Thu, 21 Apr 2022 19:02:33 UTC
The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=c7aa0304d5b5443340fc7920975743cfe2c0fca3

commit c7aa0304d5b5443340fc7920975743cfe2c0fca3
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2022-04-21 17:40:01 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2022-04-21 17:40:01 +0000

    Run softclock threads at a hardware ithread priority.
    
    Add a new PI_SOFTCLOCK for use by softclock threads.  Currently this
    maps to PI_AV which is the second-highest ithread priority.
    
    Reviewed by:    mav, kib
    Sponsored by:   Netflix
    Differential Revision:  https://reviews.freebsd.org/D33693
---
 sys/kern/kern_timeout.c | 2 +-
 sys/sys/priority.h      | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c
index db4217114c35..121ee2b13f46 100644
--- a/sys/kern/kern_timeout.c
+++ b/sys/kern/kern_timeout.c
@@ -393,7 +393,7 @@ start_softclock(void *dummy)
 		cc->cc_thread = td;
 		thread_lock(td);
 		sched_class(td, PRI_ITHD);
-		sched_prio(td, PI_SWI(SWI_CLOCK));
+		sched_prio(td, PI_SOFTCLOCK);
 		TD_SET_IWAIT(td);
 		thread_lock_set(td, (struct mtx *)&cc->cc_lock);
 		thread_unlock(td);
diff --git a/sys/sys/priority.h b/sys/sys/priority.h
index 60327cf20293..428be2d02c68 100644
--- a/sys/sys/priority.h
+++ b/sys/sys/priority.h
@@ -87,6 +87,7 @@
 
 #define	PI_REALTIME		(PRI_MIN_ITHD + 0)
 #define	PI_AV			(PRI_MIN_ITHD + 4)
+#define	PI_SOFTCLOCK		PI_AV
 #define	PI_NET			(PRI_MIN_ITHD + 8)
 #define	PI_DISK			(PRI_MIN_ITHD + 12)
 #define	PI_TTY			(PRI_MIN_ITHD + 16)