git: 6437872c1d66 - main - New sysctl to disable NOMATCH until devmatch runs

The branch main has been updated by cperciva:

URL: https://cgit.FreeBSD.org/src/commit/?id=6437872c1d665c2605f54e8ff040b0ba41edad07

commit 6437872c1d665c2605f54e8ff040b0ba41edad07
Author:     Isaac Cilia Attard <iciliaat@gmail.com>
AuthorDate: 2024-04-29 20:44:27 +0000
Commit:     Colin Percival <cperciva@FreeBSD.org>
CommitDate: 2024-05-10 00:56:40 +0000

    New sysctl to disable NOMATCH until devmatch runs
    
    Introduce hw.bus.devctl_nomatch_enabled and use it to suppress NOMATCH
    until devmatch runs
    
    There's a lot of NOMATCH events generated at boot. We also run devmatch
    once during early boot to load unmatched devices. To avoid redundant
    work, don't start generating NOMATCH events until after devmatch runs.
    Set hw.bus.devctl_nomatch_enabled=1 just before we run devmatch. The
    kernel will suppress NOMATCH events until this is set to true.
    
    This saves about 170ms from the boot on aarch64 running atop Apple
    M-series processors and the VMWare Fusion hypervisor.
    
    Reviewed by:    imp, cperciva
    MFC after:      3 days
    Sponsored by:   Google Summer of Code
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1213
---
 libexec/rc/rc.d/devmatch | 1 +
 sys/kern/kern_devctl.c   | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libexec/rc/rc.d/devmatch b/libexec/rc/rc.d/devmatch
index 78050cfa4541..67bb14761614 100755
--- a/libexec/rc/rc.d/devmatch
+++ b/libexec/rc/rc.d/devmatch
@@ -46,6 +46,7 @@ devmatch_start()
 	if [ -n "$one_nomatch" ]; then
 		list=$(devmatch -p "${one_nomatch}" | sort -u)
 	else
+		sysctl hw.bus.devctl_nomatch_enabled=1
 		list=$(devmatch | sort -u)
 	fi
 
diff --git a/sys/kern/kern_devctl.c b/sys/kern/kern_devctl.c
index 12d4f9ebfc4d..0dd05a49c9ad 100644
--- a/sys/kern/kern_devctl.c
+++ b/sys/kern/kern_devctl.c
@@ -89,6 +89,9 @@ static int sysctl_devctl_queue(SYSCTL_HANDLER_ARGS);
 static int devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_queue, CTLTYPE_INT | CTLFLAG_RWTUN |
     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_queue, "I", "devctl queue length");
+static bool nomatch_enabled = false;
+SYSCTL_BOOL(_hw_bus, OID_AUTO, devctl_nomatch_enabled, CTLFLAG_RWTUN,
+    &nomatch_enabled, 0, "enable nomatch events");
 
 static void devctl_attach_handler(void *arg __unused, device_t dev);
 static void devctl_detach_handler(void *arg __unused, device_t dev,
@@ -208,7 +211,8 @@ devctl_detach_handler(void *arg __unused, device_t dev, enum evhdev_detach state
 static void
 devctl_nomatch_handler(void *arg __unused, device_t dev)
 {
-	devaddq("?", "", dev);
+	if (nomatch_enabled)
+		devaddq("?", "", dev);
 }
 
 static int