rename scheduler->swapper and SI_SUB_RUN_SCHEDULER->SI_SUB_LAST

Also directly call swapper() at the end of mi_startup instead of
relying on swapper being the last thing in sysinits order.

Rationale:

- "RUN_SCHEDULER" was misleading, scheduling already takes place at that stage
- "scheduler" was misleading, the function swaps in the swapped out processes
- another SYSINIT(SI_SUB_RUN_SCHEDULER, SI_ORDER_ANY) could never be
  invoked depending on its relative order with scheduler; this was not obvious
  and the bug actually used to exist

Reviewed by:	kib (ealier version)
MFC after:	14 days
This commit is contained in:
Andriy Gapon 2013-07-24 09:45:31 +00:00
parent 886dbd270f
commit 785797c341
9 changed files with 22 additions and 33 deletions

View File

@ -136,7 +136,7 @@ oktousecallout(void *data __unused)
{
calloutok = 1;
}
SYSINIT(gdbhack, SI_SUB_RUN_SCHEDULER, SI_ORDER_MIDDLE, oktousecallout, NULL);
SYSINIT(gdbhack, SI_SUB_LAST, SI_ORDER_MIDDLE, oktousecallout, NULL);
static void
gdb_cnputc(struct consdev *cp, int c)

View File

@ -243,9 +243,6 @@ mi_startup(void)
/*
* Traverse the (now) ordered list of system initialization tasks.
* Perform each task, and continue on to the next task.
*
* The last item on the list is expected to be the scheduler,
* which will not return.
*/
for (sipp = sysinit; sipp < sysinit_end; sipp++) {
@ -303,7 +300,13 @@ mi_startup(void)
}
}
panic("Shouldn't get here!");
mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
mtx_unlock(&Giant);
/*
* Now hand over this thread to swapper.
*/
swapper();
/* NOTREACHED*/
}
@ -346,7 +349,7 @@ static char wit_warn[] =
"WARNING: WITNESS option enabled, expect reduced performance.\n";
SYSINIT(witwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 1,
print_caddr_t, wit_warn);
SYSINIT(witwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 1,
SYSINIT(witwarn2, SI_SUB_LAST, SI_ORDER_THIRD + 1,
print_caddr_t, wit_warn);
#endif
@ -355,7 +358,7 @@ static char diag_warn[] =
"WARNING: DIAGNOSTIC option enabled, expect reduced performance.\n";
SYSINIT(diagwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 2,
print_caddr_t, diag_warn);
SYSINIT(diagwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 2,
SYSINIT(diagwarn2, SI_SUB_LAST, SI_ORDER_THIRD + 2,
print_caddr_t, diag_warn);
#endif

View File

@ -1051,5 +1051,5 @@ start_periodic_resettodr(void *arg __unused)
periodic_resettodr, NULL);
}
SYSINIT(periodic_resettodr, SI_SUB_RUN_SCHEDULER, SI_ORDER_MIDDLE,
SYSINIT(periodic_resettodr, SI_SUB_LAST, SI_ORDER_MIDDLE,
start_periodic_resettodr, NULL);

View File

@ -143,7 +143,7 @@ static struct kproc_desc sched_kp = {
schedcpu_thread,
NULL
};
SYSINIT(schedcpu, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, kproc_start,
SYSINIT(schedcpu, SI_SUB_LAST, SI_ORDER_FIRST, kproc_start,
&sched_kp);
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL);

View File

@ -68,17 +68,17 @@ _module_run(void *arg)
}
#define module_init(fn) \
SYSINIT(fn, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, _module_run, (fn))
SYSINIT(fn, SI_SUB_LAST, SI_ORDER_FIRST, _module_run, (fn))
/*
* XXX This is a freebsdism designed to work around not having a module
* load order resolver built in.
*/
#define module_init_order(fn, order) \
SYSINIT(fn, SI_SUB_RUN_SCHEDULER, (order), _module_run, (fn))
SYSINIT(fn, SI_SUB_LAST, (order), _module_run, (fn))
#define module_exit(fn) \
SYSUNINIT(fn, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, _module_run, (fn))
SYSUNINIT(fn, SI_SUB_LAST, SI_ORDER_FIRST, _module_run, (fn))
#define module_get(module)
#define module_put(module)

View File

@ -79,7 +79,7 @@ extern volatile int ticks;
* enumeration values are explicit rather than implicit to provide
* for binary compatibility with inserted elements.
*
* The SI_SUB_RUN_SCHEDULER value must have the highest lexical value.
* The SI_SUB_LAST value must have the highest lexical value.
*
* The SI_SUB_SWAP values represent a value used by
* the BSD 4.4Lite but not by FreeBSD; it is maintained in dependent
@ -165,7 +165,7 @@ enum sysinit_sub_id {
SI_SUB_KTHREAD_IDLE = 0xee00000, /* idle procs*/
SI_SUB_SMP = 0xf000000, /* start the APs*/
SI_SUB_RACCTD = 0xf100000, /* start raccd*/
SI_SUB_RUN_SCHEDULER = 0xfffffff /* scheduler*/
SI_SUB_LAST = 0xfffffff /* final initialization */
};

View File

@ -182,7 +182,7 @@ static void name ## _add_proc(void *dummy __unused) \
#name, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, \
ptr, 0, sysctl_dpcpu_long, "LU", descr); \
} \
SYSINIT(name, SI_SUB_RUN_SCHEDULER, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
SYSINIT(name, SI_SUB_LAST, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
#define SCHED_STAT_DEFINE(name, descr) \
DPCPU_DEFINE(unsigned long, name); \

View File

@ -147,6 +147,7 @@ int swap_reserve_by_cred(vm_ooffset_t incr, struct ucred *cred);
void swap_reserve_force(vm_ooffset_t incr);
void swap_release(vm_ooffset_t decr);
void swap_release_by_cred(vm_ooffset_t decr, struct ucred *cred);
void swapper(void);
#endif /* VM_H */

View File

@ -96,16 +96,6 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_pager.h>
#include <vm/swap_pager.h>
/*
* System initialization
*
* THIS MUST BE THE LAST INITIALIZATION ITEM!!!
*
* Note: run scheduling should be divorced from the vm system.
*/
static void scheduler(void *);
SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_ANY, scheduler, NULL);
#ifndef NO_SWAPPING
static int swapout(struct proc *);
static void swapclear(struct proc *);
@ -695,10 +685,8 @@ faultin(p)
*
* Giant is held on entry.
*/
/* ARGSUSED*/
static void
scheduler(dummy)
void *dummy;
void
swapper(void)
{
struct proc *p;
struct thread *td;
@ -708,9 +696,6 @@ scheduler(dummy)
int ppri;
int pri;
mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
mtx_unlock(&Giant);
loop:
if (vm_page_count_min()) {
VM_WAIT;
@ -761,7 +746,7 @@ scheduler(dummy)
* Nothing to do, back to sleep.
*/
if ((p = pp) == NULL) {
tsleep(&proc0, PVM, "sched", MAXSLP * hz / 2);
tsleep(&proc0, PVM, "swapin", MAXSLP * hz / 2);
goto loop;
}
PROC_LOCK(p);