Have cpu_throw() loop on blocked_lock as well. This bug has existed

a long time and has gone unnoticed just as long, because I kept
using sched_4bsd (due to sched_ule not working with preemption),
but GENERIC had sched_ule by default -- including SMP.

While here, remove unused inclusion of <machine/clock.h>, remove
totally bogus inclusion of <i386/include/specialreg.h>.
This commit is contained in:
Marcel Moolenaar 2010-03-15 16:53:09 +00:00
parent 0a47b5f57f
commit 510e1af7cb

View File

@ -80,7 +80,6 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_pager.h>
#include <machine/bootinfo.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/efi.h>
#include <machine/elf.h>
@ -100,8 +99,6 @@ __FBSDID("$FreeBSD$");
#include <machine/unwind.h>
#include <machine/vmparam.h>
#include <i386/include/specialreg.h>
SYSCTL_NODE(_hw, OID_AUTO, freq, CTLFLAG_RD, 0, "");
SYSCTL_NODE(_machdep, OID_AUTO, cpu, CTLFLAG_RD, 0, "");
@ -450,18 +447,22 @@ cpu_switch(struct thread *old, struct thread *new, struct mtx *mtx)
old->td_frame->tf_special.psr |= IA64_PSR_DFH;
if (!savectx(oldpcb)) {
atomic_store_rel_ptr(&old->td_lock, mtx);
#if defined(SCHED_ULE) && defined(SMP)
/* td_lock is volatile */
while (new->td_lock == &blocked_lock)
;
#endif
newpcb = new->td_pcb;
oldpcb->pcb_current_pmap =
pmap_switch(newpcb->pcb_current_pmap);
#if defined(SCHED_ULE) && defined(SMP)
while (atomic_load_acq_ptr(&new->td_lock) == &blocked_lock)
cpu_spinwait();
#endif
PCPU_SET(curthread, new);
#ifdef COMPAT_FREEBSD32
ia32_restorectx(newpcb);
#endif
if (PCPU_GET(fpcurthread) == new)
new->td_frame->tf_special.psr &= ~IA64_PSR_DFH;
restorectx(newpcb);
@ -478,10 +479,18 @@ cpu_throw(struct thread *old __unused, struct thread *new)
newpcb = new->td_pcb;
(void)pmap_switch(newpcb->pcb_current_pmap);
#if defined(SCHED_ULE) && defined(SMP)
while (atomic_load_acq_ptr(&new->td_lock) == &blocked_lock)
cpu_spinwait();
#endif
PCPU_SET(curthread, new);
#ifdef COMPAT_FREEBSD32
ia32_restorectx(newpcb);
#endif
restorectx(newpcb);
/* We should not get here. */
panic("cpu_throw: restorectx() returned");