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MF amd64 r233097, r233122

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With the changes over the past year to how accesses to the page's dirty
field are synchronized, there is no need for pmap_protect() to acquire
the page queues lock unless it is going to access the pv lists or
PMAP1/PADDR1.

Style fix to pmap_protect().
This commit is contained in:
Alan Cox 2012-05-24 15:25:35 +00:00
parent f6ad3f237a
commit 4e65634580
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=235912
1 changed files with 35 additions and 12 deletions
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47
sys/i386/i386/pmap.c
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@ -3050,7 +3050,7 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
vm_offset_t pdnxt;
pd_entry_t ptpaddr;
pt_entry_t *pte;
int anychanged;
boolean_t anychanged, pv_lists_locked;
if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
pmap_remove(pmap, sva, eva);
@ -3066,10 +3066,16 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
return;
#endif
anychanged = 0;
if (pmap_is_current(pmap))
pv_lists_locked = FALSE;
else {
pv_lists_locked = TRUE;
resume:
vm_page_lock_queues();
sched_pin();
}
anychanged = FALSE;
vm_page_lock_queues();
sched_pin();
PMAP_LOCK(pmap);
for (; sva < eva; sva = pdnxt) {
pt_entry_t obits, pbits;
@ -3104,12 +3110,27 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
*/
if (pmap_protect_pde(pmap,
&pmap->pm_pdir[pdirindex], sva, prot))
anychanged = 1;
continue;
} else if (!pmap_demote_pde(pmap,
&pmap->pm_pdir[pdirindex], sva)) {
/* The large page mapping was destroyed. */
anychanged = TRUE;
continue;
} else {
if (!pv_lists_locked) {
pv_lists_locked = TRUE;
if (!mtx_trylock(&vm_page_queue_mtx)) {
if (anychanged)
pmap_invalidate_all(
pmap);
PMAP_UNLOCK(pmap);
goto resume;
}
}
if (!pmap_demote_pde(pmap,
&pmap->pm_pdir[pdirindex], sva)) {
/*
* The large page mapping was
* destroyed.
*/
continue;
}
}
}
@ -3155,14 +3176,16 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
if (obits & PG_G)
pmap_invalidate_page(pmap, sva);
else
anychanged = 1;
anychanged = TRUE;
}
}
}
sched_unpin();
if (anychanged)
pmap_invalidate_all(pmap);
vm_page_unlock_queues();
if (pv_lists_locked) {
sched_unpin();
vm_page_unlock_queues();
}
PMAP_UNLOCK(pmap);
}