git: 133935d26f20 - main - pf: atomically increment state ids

The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=133935d26f20c0b9c433da9a2b32bcbe562bc2c5

commit 133935d26f20c0b9c433da9a2b32bcbe562bc2c5
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2022-10-07 17:17:06 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2022-10-08 16:27:29 +0000

    pf: atomically increment state ids
    
    Rather than using a per-cpu state counter, and adding in the CPU id we
    can atomically increment the number.
    This has the advantage of removing the assumption that the CPU ID fits
    in 8 bits.
    
    Event:          Aberdeen Hackathon 2022
    Reviewed by:    mjg
    Differential Revision:  https://reviews.freebsd.org/D36915
---
 sys/net/pfvar.h           |  2 +-
 sys/netpfil/pf/pf.c       | 12 ++----------
 sys/netpfil/pf/pf_ioctl.c |  6 +-----
 3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/sys/net/pfvar.h b/sys/net/pfvar.h
index 16ee0b55e2e8..3773a797776d 100644
--- a/sys/net/pfvar.h
+++ b/sys/net/pfvar.h
@@ -1987,7 +1987,7 @@ VNET_DECLARE(void *, pf_swi_cookie);
 VNET_DECLARE(struct intr_event *, pf_swi_ie);
 #define	V_pf_swi_ie	VNET(pf_swi_ie)
 
-VNET_DECLARE(uint64_t, pf_stateid[MAXCPU]);
+VNET_DECLARE(struct unrhdr64, pf_stateid);
 #define	V_pf_stateid	VNET(pf_stateid)
 
 TAILQ_HEAD(pf_altqqueue, pf_altq);
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index 33ef5119ee3c..2a6efbfe6e7d 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -249,12 +249,7 @@ uma_zone_t		pf_mtag_z;
 VNET_DEFINE(uma_zone_t,	 pf_state_z);
 VNET_DEFINE(uma_zone_t,	 pf_state_key_z);
 
-VNET_DEFINE(uint64_t, pf_stateid[MAXCPU]);
-#define	PFID_CPUBITS	8
-#define	PFID_CPUSHIFT	(sizeof(uint64_t) * NBBY - PFID_CPUBITS)
-#define	PFID_CPUMASK	((uint64_t)((1 << PFID_CPUBITS) - 1) <<	PFID_CPUSHIFT)
-#define	PFID_MAXID	(~PFID_CPUMASK)
-CTASSERT((1 << PFID_CPUBITS) >= MAXCPU);
+VNET_DEFINE(struct unrhdr64, pf_stateid);
 
 static void		 pf_src_tree_remove_state(struct pf_kstate *);
 static void		 pf_init_threshold(struct pf_threshold *, u_int32_t,
@@ -1416,10 +1411,7 @@ pf_state_insert(struct pfi_kkif *kif, struct pfi_kkif *orig_kif,
 	s->orig_kif = orig_kif;
 
 	if (s->id == 0 && s->creatorid == 0) {
-		/* XXX: should be atomic, but probability of collision low */
-		if ((s->id = V_pf_stateid[curcpu]++) == PFID_MAXID)
-			V_pf_stateid[curcpu] = 1;
-		s->id |= (uint64_t )curcpu << PFID_CPUSHIFT;
+		s->id = alloc_unr64(&V_pf_stateid);
 		s->id = htobe64(s->id);
 		s->creatorid = V_pf_status.hostid;
 	}
diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
index 67422cc43997..e7a5bb084ee5 100644
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -2595,16 +2595,12 @@ pfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td
 		if (V_pf_status.running)
 			error = EEXIST;
 		else {
-			int cpu;
-
 			hook_pf();
 			if (! TAILQ_EMPTY(V_pf_keth->active.rules))
 				hook_pf_eth();
 			V_pf_status.running = 1;
 			V_pf_status.since = time_second;
-
-			CPU_FOREACH(cpu)
-				V_pf_stateid[cpu] = time_second;
+			new_unrhdr64(&V_pf_stateid, time_second);
 
 			DPFPRINTF(PF_DEBUG_MISC, ("pf: started\n"));
 		}