git: 69413598d266 - main - signal: use proc_iterate to save on work

The branch main has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=69413598d2660054e29cac9454fe18c08e3bf36d

commit 69413598d2660054e29cac9454fe18c08e3bf36d
Author:     Mateusz Guzik <mjg@FreeBSD.org>
AuthorDate: 2022-03-10 18:58:12 +0000
Commit:     Mateusz Guzik <mjg@FreeBSD.org>
CommitDate: 2022-09-05 11:54:47 +0000

    signal: use proc_iterate to save on work
    
    Most notably poudriere performs kill -9 -1 in jails for each port
    being built. This reduces the scan from hundrends of processes to
    literally 1.
    
    Reviewed by:    jamie, markj
    Differential Revision:  https://reviews.freebsd.org/D34522
---
 sys/kern/kern_sig.c | 39 ++++++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 6fd3eca0a14e..c50a37de07e6 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1776,18 +1776,13 @@ struct killpg1_ctx {
 };
 
 static void
-killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg)
+killpg1_sendsig_locked(struct proc *p, struct killpg1_ctx *arg)
 {
 	int err;
 
-	if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 ||
-	    (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW)
-		return;
-	PROC_LOCK(p);
 	err = p_cansignal(arg->td, p, arg->sig);
 	if (err == 0 && arg->sig != 0)
 		pksignal(p, arg->sig, arg->ksi);
-	PROC_UNLOCK(p);
 	if (err != ESRCH)
 		arg->found = true;
 	if (err == 0)
@@ -1796,6 +1791,31 @@ killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg)
 		arg->ret = err;
 }
 
+static void
+killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg)
+{
+
+	if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 ||
+	    (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW)
+		return;
+
+	PROC_LOCK(p);
+	killpg1_sendsig_locked(p, arg);
+	PROC_UNLOCK(p);
+}
+
+static void
+kill_processes_prison_cb(struct proc *p, void *arg)
+{
+	struct killpg1_ctx *ctx = arg;
+
+	if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 ||
+	    (p == ctx->td->td_proc) || p->p_state == PRS_NEW)
+		return;
+
+	killpg1_sendsig_locked(p, ctx);
+}
+
 /*
  * Common code for kill process group/broadcast kill.
  * cp is calling process.
@@ -1817,11 +1837,8 @@ killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
 		/*
 		 * broadcast
 		 */
-		sx_slock(&allproc_lock);
-		FOREACH_PROC_IN_SYSTEM(p) {
-			killpg1_sendsig(p, true, &arg);
-		}
-		sx_sunlock(&allproc_lock);
+		prison_proc_iterate(td->td_ucred->cr_prison,
+		    kill_processes_prison_cb, &arg);
 	} else {
 		sx_slock(&proctree_lock);
 		if (pgid == 0) {