d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

MF amd64 r233097, r233122

Browse Source 
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
1 changed files with 35 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
sys/i386/i386/pmap.c
View File

@ -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);
}