git: dfe172484d0e - main - sigtd(): prefer non-stopped thread as a target for signal queue

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=dfe172484d0e1de0bb32bcab8775eb83e15031c0

commit dfe172484d0e1de0bb32bcab8775eb83e15031c0
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2023-07-21 09:41:39 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2023-07-26 15:12:55 +0000

    sigtd(): prefer non-stopped thread as a target for signal queue
    
    This should improve signal delivery latency and better expose the
    process state to the executing threads.
    
    Reviewed by:    markj
    Tested by:      pho
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D41128
---
 sys/kern/kern_sig.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index de42255017d8..5876e2e93920 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2157,14 +2157,18 @@ sigtd(struct proc *p, int sig, bool fast_sigblock)
 	if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) &&
 	    (!fast_sigblock || curthread->td_sigblock_val == 0))
 		return (curthread);
+
+	/* Find a non-stopped thread that does not mask the signal. */
 	signal_td = NULL;
 	FOREACH_THREAD_IN_PROC(p, td) {
 		if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock ||
-		    td != curthread || td->td_sigblock_val == 0)) {
+		    td != curthread || td->td_sigblock_val == 0) &&
+		    (td->td_flags & TDF_BOUNDARY) == 0) {
 			signal_td = td;
 			break;
 		}
 	}
+	/* Select random (first) thread if no better match was found. */
 	if (signal_td == NULL)
 		signal_td = FIRST_THREAD_IN_PROC(p);
 	return (signal_td);