The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=6c2e9f4c32a44f3c239aba346322d871097eaed0
commit 6c2e9f4c32a44f3c239aba346322d871097eaed0
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2022-09-24 13:20:29 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2022-09-24 13:28:41 +0000
amd64: Handle 1GB mappings in pmap_enter_quick_locked()
This code path can be triggered by applying MADV_WILLNEED to a 1GB
mapping.
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D36674
---
sys/amd64/amd64/pmap.c | 39 ++++++++++++++++++++++-----------------
1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 9a33298944cc..358d016676d2 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -7545,8 +7545,9 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va,
vm_page_t m,
* resident, we are creating it here.
*/
if (va < VM_MAXUSER_ADDRESS) {
+ pdp_entry_t *pdpe;
+ pd_entry_t *pde;
vm_pindex_t ptepindex;
- pd_entry_t *ptepa;
/*
* Calculate pagetable page index
@@ -7555,31 +7556,35 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va,
vm_page_t m,
if (mpte && (mpte->pindex == ptepindex)) {
mpte->ref_count++;
} else {
- /*
- * Get the page directory entry
- */
- ptepa = pmap_pde(pmap, va);
-
/*
* If the page table page is mapped, we just increment
* the hold count, and activate it. Otherwise, we
- * attempt to allocate a page table page. If this
- * attempt fails, we don't retry. Instead, we give up.
+ * attempt to allocate a page table page, passing NULL
+ * instead of the PV list lock pointer because we don't
+ * intend to sleep. If this attempt fails, we don't
+ * retry. Instead, we give up.
*/
- if (ptepa && (*ptepa & PG_V) != 0) {
- if (*ptepa & PG_PS)
+ pdpe = pmap_pdpe(pmap, va);
+ if (pdpe != NULL && (*pdpe & PG_V) != 0) {
+ if ((*pdpe & PG_PS) != 0)
return (NULL);
- mpte = PHYS_TO_VM_PAGE(*ptepa & PG_FRAME);
- mpte->ref_count++;
+ pde = pmap_pdpe_to_pde(pdpe, va);
+ if ((*pde & PG_V) != 0) {
+ if ((*pde & PG_PS) != 0)
+ return (NULL);
+ mpte = PHYS_TO_VM_PAGE(*pde & PG_FRAME);
+ mpte->ref_count++;
+ } else {
+ mpte = pmap_allocpte_alloc(pmap,
+ ptepindex, NULL, va);
+ if (mpte == NULL)
+ return (NULL);
+ }
} else {
- /*
- * Pass NULL instead of the PV list lock
- * pointer, because we don't intend to sleep.
- */
mpte = pmap_allocpte_alloc(pmap, ptepindex,
NULL, va);
if (mpte == NULL)
- return (mpte);
+ return (NULL);
}
}
pte = (pt_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mpte));
