git: 1f68ca5802db - main - vt: Do not lock request comming from terminal

The branch main has been updated by ray:

URL: https://cgit.FreeBSD.org/src/commit/?id=1f68ca5802db91bd9725bcdbf55932e104dbe95d

commit 1f68ca5802db91bd9725bcdbf55932e104dbe95d
Author:     Aleksandr Rybalko <ray@FreeBSD.org>
AuthorDate: 2026-06-11 13:33:49 +0000
Commit:     Aleksandr Rybalko <ray@FreeBSD.org>
CommitDate: 2026-06-11 23:56:03 +0000

    vt: Do not lock request comming from terminal
    
    only those originated by mouse.  Because the terminal surrounds
    requests to vt(4) with locking.
    
    Reported by:    bz, adrian
    Reviewed by:    adrian, glebius
    Approved by:    glebius (mentor)
    MFC after:      2 weeks
    Differential Revision:  https://reviews.freebsd.org/D57442
---
 sys/dev/vt/vt_buf.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/sys/dev/vt/vt_buf.c b/sys/dev/vt/vt_buf.c
index 9b65a7cb889c..ec08967232f4 100644
--- a/sys/dev/vt/vt_buf.c
+++ b/sys/dev/vt/vt_buf.c
@@ -45,6 +45,7 @@ static MALLOC_DEFINE(M_VTBUF, "vtbuf", "vt buffer");
 
 #define	VTBUF_LOCK(vb)		mtx_lock_spin(&(vb)->vb_lock)
 #define	VTBUF_UNLOCK(vb)	mtx_unlock_spin(&(vb)->vb_lock)
+#define	VTBUF_LOCK_OWNED(vb)	mtx_owned(&(vb)->vb_lock)
 
 #define POS_INDEX(c, r) (((r) << 12) + (c))
 #define	POS_COPY(d, s)	do {	\
@@ -740,9 +741,19 @@ vtbuf_flush_mark(struct vt_buf *vb)
 		area.tr_end.tp_col = vb->vb_scr_size.tp_col;
 		area.tr_end.tp_row = MAX(s, e) + 1;
 
-		VTBUF_LOCK(vb);
-		vtbuf_dirty(vb, &area);
-		VTBUF_UNLOCK(vb);
+		/* 
+		 * If the request originates from a keyboard, the vtbuf is
+		 * locked by teken for the entire duration of the request.
+		 * For all other sources, we avoid holding the spinlock for
+		 * extended periods.
+		 */
+		if (VTBUF_LOCK_OWNED(vb)) {
+			vtbuf_dirty(vb, &area);
+		} else {
+			VTBUF_LOCK(vb);
+			vtbuf_dirty(vb, &area);
+			VTBUF_UNLOCK(vb);
+		}
 	}
 }