diff options
| author | jeff <jeff@FreeBSD.org> | 2007-05-20 22:03:57 +0000 |
|---|---|---|
| committer | jeff <jeff@FreeBSD.org> | 2007-05-20 22:03:57 +0000 |
| commit | bcfa98d0197abe20a89b307cefcf22f4e04ac8ff (patch) | |
| tree | 75dae3b34630a5e5362696144a588236fbbf7493 /sys/i386/i386/vm_machdep.c | |
| parent | f3855854eee8165cfd604ba873b581a55f017519 (diff) | |
| download | FreeBSD-src-bcfa98d0197abe20a89b307cefcf22f4e04ac8ff.zip FreeBSD-src-bcfa98d0197abe20a89b307cefcf22f4e04ac8ff.tar.gz | |
- Move GDT/LDT locking into a seperate spinlock, removing the global
scheduler lock from this responsibility.
Contributed by: Attilio Rao <attilio@FreeBSD.org>
Tested by: jeff, kkenn
Diffstat (limited to 'sys/i386/i386/vm_machdep.c')
| -rw-r--r-- | sys/i386/i386/vm_machdep.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index b0e4d21..116f1df 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -62,6 +62,7 @@ __FBSDID("$FreeBSD$"); #include <sys/mutex.h> #include <sys/pioctl.h> #include <sys/proc.h> +#include <sys/refcount.h> #include <sys/sf_buf.h> #include <sys/smp.h> #include <sys/sched.h> @@ -158,8 +159,9 @@ cpu_fork(td1, p2, td2, flags) struct mdproc *mdp1 = &p1->p_md; struct proc_ldt *pldt; - pldt = mdp1->md_ldt; - if (pldt && pldt->ldt_refcnt > 1) { + mtx_lock_spin(&dt_lock); + if ((pldt = mdp1->md_ldt) != NULL && + pldt->ldt_refcnt > 1) { pldt = user_ldt_alloc(mdp1, pldt->ldt_len); if (pldt == NULL) panic("could not copy LDT"); @@ -167,6 +169,7 @@ cpu_fork(td1, p2, td2, flags) set_user_ldt(mdp1); user_ldt_free(td1); } + mtx_unlock_spin(&dt_lock); } return; } @@ -248,10 +251,10 @@ cpu_fork(td1, p2, td2, flags) pcb2->pcb_ext = 0; /* Copy the LDT, if necessary. */ - mtx_lock_spin(&sched_lock); + mtx_lock_spin(&dt_lock); if (mdp2->md_ldt != NULL) { if (flags & RFMEM) { - mdp2->md_ldt->ldt_refcnt++; + refcount_acquire(&mdp2->md_ldt->ldt_refcnt); } else { mdp2->md_ldt = user_ldt_alloc(mdp2, mdp2->md_ldt->ldt_len); @@ -259,7 +262,7 @@ cpu_fork(td1, p2, td2, flags) panic("could not copy LDT"); } } - mtx_unlock_spin(&sched_lock); + mtx_unlock_spin(&dt_lock); /* Setup to release sched_lock in fork_exit(). */ td2->td_md.md_spinlock_count = 1; @@ -304,11 +307,13 @@ cpu_exit(struct thread *td) * If this process has a custom LDT, release it. Reset pc->pcb_gs * and %gs before we free it in case they refer to an LDT entry. */ + mtx_lock_spin(&dt_lock); if (td->td_proc->p_md.md_ldt) { td->td_pcb->pcb_gs = _udatasel; load_gs(_udatasel); user_ldt_free(td); } + mtx_unlock_spin(&dt_lock); } void |
