svn commit: r355024 - in head/sys: kern net sys

[Conrad Meyer]

Author: cem
Date: Fri Nov 22 23:23:40 2019
New Revision: 355024
URL: https://svnweb.freebsd.org/changeset/base/355024

Log:
  Add explicit SI_SUB_EPOCH
  
  Add explicit SI_SUB_EPOCH, after SI_SUB_TASKQ and before SI_SUB_SMP
  (EARLY_AP_STARTUP).  Rename existing "SI_SUB_TASKQ + 1" to SI_SUB_EPOCH.
  
  epoch(9) consumers cannot epoch_alloc() before SI_SUB_EPOCH:SI_ORDER_SECOND,
  but likely should allocate before SI_SUB_SMP.  Prior to this change,
  consumers (well, epoch itself, and net/if.c) just open-coded the
  SI_SUB_TASKQ + 1 order to match epoch.c, but this was fragile.
  
  Reviewed by:	mmacy
  Differential Revision:	https://reviews.freebsd.org/D22503

Modified:
  head/sys/kern/subr_epoch.c
  head/sys/net/if.c
  head/sys/sys/kernel.h

Modified: head/sys/kern/subr_epoch.c
==============================================================================
--- head/sys/kern/subr_epoch.c	Fri Nov 22 21:31:59 2019	(r355023)
+++ head/sys/kern/subr_epoch.c	Fri Nov 22 23:23:40 2019	(r355024)
@@ -276,7 +276,7 @@ epoch_init(void *arg __unused)
 	global_epoch = epoch_alloc("Global", 0);
 	global_epoch_preempt = epoch_alloc("Global preemptible", EPOCH_PREEMPT);
 }
-SYSINIT(epoch, SI_SUB_TASKQ + 1, SI_ORDER_FIRST, epoch_init, NULL);
+SYSINIT(epoch, SI_SUB_EPOCH, SI_ORDER_FIRST, epoch_init, NULL);
 
 #if !defined(EARLY_AP_STARTUP)
 static void

Modified: head/sys/net/if.c
==============================================================================
--- head/sys/net/if.c	Fri Nov 22 21:31:59 2019	(r355023)
+++ head/sys/net/if.c	Fri Nov 22 23:23:40 2019	(r355024)
@@ -933,8 +933,7 @@ if_epochalloc(void *dummy __unused)
 	net_epoch_preempt = epoch_alloc("Net preemptible", EPOCH_PREEMPT);
 	net_epoch = epoch_alloc("Net", 0);
 }
-SYSINIT(ifepochalloc, SI_SUB_TASKQ + 1, SI_ORDER_ANY,
-    if_epochalloc, NULL);
+SYSINIT(ifepochalloc, SI_SUB_EPOCH, SI_ORDER_ANY, if_epochalloc, NULL);
 
 static void
 if_attachdomain(void *dummy)

Modified: head/sys/sys/kernel.h
==============================================================================
--- head/sys/sys/kernel.h	Fri Nov 22 21:31:59 2019	(r355023)
+++ head/sys/sys/kernel.h	Fri Nov 22 23:23:40 2019	(r355024)
@@ -124,6 +124,7 @@ enum sysinit_sub_id {
 	SI_SUB_MBUF		= 0x2700000,	/* mbuf subsystem */
 	SI_SUB_INTR		= 0x2800000,	/* interrupt threads */
 	SI_SUB_TASKQ		= 0x2880000,	/* task queues */
+	SI_SUB_EPOCH		= 0x2888000,	/* epoch subsystem */
 #ifdef EARLY_AP_STARTUP
 	SI_SUB_SMP		= 0x2900000,	/* start the APs*/
 #endif