FreeBSD: Create taskq threads in appropriate proc

Stepping stone toward re-enabling spa_thread on FreeBSD.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10715

include/os/freebsd/spl/sys/proc.h

@@ -61,13 +61,14 @@ typedef	struct thread	kthread_t;
 typedef struct thread	*kthread_id_t;
 typedef struct proc	proc_t;
 
-extern struct proc *zfsproc;
+extern proc_t *system_proc;
 
 static __inline kthread_t *
 do_thread_create(caddr_t stk, size_t stksize, void (*proc)(void *), void *arg,
     size_t len, proc_t *pp, int state, pri_t pri, const char *name)
 {
 	kthread_t *td = NULL;
+	proc_t **ppp;
 	int error;
 
 	/*
@@ -77,8 +78,12 @@ do_thread_create(caddr_t stk, size_t stksize, void (*proc)(void *), void *arg,
 	ASSERT(len == 0);
 	ASSERT(state == TS_RUN);
 
-	error = kproc_kthread_add(proc, arg, &zfsproc, &td,
-	    RFSTOPPED, stksize / PAGE_SIZE, "zfskern", "%s", name);
+	if (pp == &p0)
+		ppp = &system_proc;
+	else
+		ppp = &pp;
+	error = kproc_kthread_add(proc, arg, ppp, &td, RFSTOPPED,
+	    stksize / PAGE_SIZE, "zfskern", "%s", name);
 	if (error == 0) {
 		thread_lock(td);
 		sched_prio(td, pri);

module/os/freebsd/spl/spl_sysevent.c

@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <sys/kmem.h>
 #include <sys/list.h>
+#include <sys/proc.h>
 #include <sys/sbuf.h>
 #include <sys/nvpair.h>
 #include <sys/sunddi.h>
@@ -256,6 +257,6 @@ sysevent_worker(void *arg __unused)
 void
 ddi_sysevent_init(void)
 {
-	kproc_kthread_add(sysevent_worker, NULL, &zfsproc, NULL, 0, 0,
+	kproc_kthread_add(sysevent_worker, NULL, &system_proc, NULL, 0, 0,
 	    "zfskern", "sysevent");
 }

module/os/freebsd/spl/spl_taskq.c

@@ -44,6 +44,11 @@ __FBSDID("$FreeBSD$");
 
 #include <vm/uma.h>
 
+#if __FreeBSD_version < 1201522
+#define	taskqueue_start_threads_in_proc(tqp, count, pri, proc, name, ...) \
+    taskqueue_start_threads(tqp, count, pri, name, __VA_ARGS__)
+#endif
+
 static uint_t taskq_tsd;
 static uma_zone_t taskq_zone;
 
@@ -51,6 +56,8 @@ taskq_t *system_taskq = NULL;
 taskq_t *system_delay_taskq = NULL;
 taskq_t *dynamic_taskq = NULL;
 
+proc_t *system_proc;
+
 extern int uma_align_cache;
 
 static MALLOC_DEFINE(M_TASKQ, "taskq", "taskq structures");
@@ -166,8 +173,8 @@ taskq_tsd_set(void *context)
 }
 
 static taskq_t *
-taskq_create_with_init(const char *name, int nthreads, pri_t pri,
-    int minalloc __unused, int maxalloc __unused, uint_t flags)
+taskq_create_impl(const char *name, int nthreads, pri_t pri,
+    proc_t *proc __maybe_unused, uint_t flags)
 {
 	taskq_t *tq;
 
@@ -181,8 +188,8 @@ taskq_create_with_init(const char *name, int nthreads, pri_t pri,
 	    taskq_tsd_set, tq);
 	taskqueue_set_callback(tq->tq_queue, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN,
 	    taskq_tsd_set, NULL);
-	(void) taskqueue_start_threads(&tq->tq_queue, nthreads, pri,
-	    "%s", name);
+	(void) taskqueue_start_threads_in_proc(&tq->tq_queue, nthreads, pri,
+	    proc, "%s", name);
 
 	return ((taskq_t *)tq);
 }
@@ -191,18 +198,14 @@ taskq_t *
 taskq_create(const char *name, int nthreads, pri_t pri, int minalloc __unused,
     int maxalloc __unused, uint_t flags)
 {
-
-	return (taskq_create_with_init(name, nthreads, pri, minalloc, maxalloc,
-	    flags));
+	return (taskq_create_impl(name, nthreads, pri, system_proc, flags));
 }
 
 taskq_t *
-taskq_create_proc(const char *name, int nthreads, pri_t pri, int minalloc,
-    int maxalloc, proc_t *proc __unused, uint_t flags)
+taskq_create_proc(const char *name, int nthreads, pri_t pri,
+    int minalloc __unused, int maxalloc __unused, proc_t *proc, uint_t flags)
 {
-
-	return (taskq_create_with_init(name, nthreads, pri, minalloc, maxalloc,
-	    flags));
+	return (taskq_create_impl(name, nthreads, pri, proc, flags));
 }
 
 void

module/os/freebsd/zfs/zvol_os.c

@@ -60,6 +60,7 @@
 #include <sys/conf.h>
 #include <sys/cmn_err.h>
 #include <sys/stat.h>
+#include <sys/proc.h>
 #include <sys/zap.h>
 #include <sys/spa.h>
 #include <sys/spa_impl.h>
@@ -135,8 +136,6 @@ struct zvol_state_os {
 	} _zso_state;
 };
 
-struct proc *zfsproc;
-
 static uint32_t zvol_minors;
 
 SYSCTL_DECL(_vfs_zfs);
@@ -385,7 +384,7 @@ zvol_geom_run(zvol_state_t *zv)
 
 	g_error_provider(pp, 0);
 
-	kproc_kthread_add(zvol_geom_worker, zv, &zfsproc, NULL, 0, 0,
+	kproc_kthread_add(zvol_geom_worker, zv, &system_proc, NULL, 0, 0,
 	    "zfskern", "zvol %s", pp->name + sizeof (ZVOL_DRIVER));
 }