The branch main has been updated by alc:
URL:
https://cgit.FreeBSD.org/src/commit/?id=1d5ebad06c20b1aed3b0c323c4675678afec5e55
commit 1d5ebad06c20b1aed3b0c323c4675678afec5e55
Author: Alan Cox <a...@freebsd.org>
AuthorDate: 2022-09-30 06:54:02 +0000
Commit: Alan Cox <a...@freebsd.org>
CommitDate: 2022-09-30 17:14:05 +0000
pmap: optimize MADV_WILLNEED on existing superpages
Specifically, avoid pointless calls to pmap_enter_quick_locked() when
madvise(MADV_WILLNEED) is applied to an existing superpage mapping.
Reported by: mhorne
Reviewed by: kib, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D36801
---
sys/amd64/amd64/pmap.c | 64 +++++++++++++++++++++++++++++++-------------------
sys/arm64/arm64/pmap.c | 59 +++++++++++++++++++++++++++-------------------
2 files changed, 75 insertions(+), 48 deletions(-)
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index f4df664f0cca..b9b031d55d7d 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -1258,7 +1258,7 @@ static boolean_t pmap_demote_pde_locked(pmap_t pmap,
pd_entry_t *pde,
vm_offset_t va, struct rwlock **lockp);
static boolean_t pmap_demote_pdpe(pmap_t pmap, pdp_entry_t *pdpe,
vm_offset_t va);
-static bool pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m,
+static int pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m,
vm_prot_t prot, struct rwlock **lockp);
static int pmap_enter_pde(pmap_t pmap, vm_offset_t va, pd_entry_t newpde,
u_int flags, vm_page_t m, struct rwlock **lockp);
@@ -7271,13 +7271,12 @@ out:
}
/*
- * Tries to create a read- and/or execute-only 2MB page mapping. Returns true
- * if successful. Returns false if (1) a page table page cannot be allocated
- * without sleeping, (2) a mapping already exists at the specified virtual
- * address, or (3) a PV entry cannot be allocated without reclaiming another
- * PV entry.
+ * Tries to create a read- and/or execute-only 2MB page mapping. Returns
+ * KERN_SUCCESS if the mapping was created. Otherwise, returns an error
+ * value. See pmap_enter_pde() for the possible error values when "no sleep",
+ * "no replace", and "no reclaim" are specified.
*/
-static bool
+static int
pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
struct rwlock **lockp)
{
@@ -7295,8 +7294,7 @@ pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t
m, vm_prot_t prot,
if (va < VM_MAXUSER_ADDRESS)
newpde |= PG_U;
return (pmap_enter_pde(pmap, va, newpde, PMAP_ENTER_NOSLEEP |
- PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, NULL, lockp) ==
- KERN_SUCCESS);
+ PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, NULL, lockp));
}
/*
@@ -7319,12 +7317,19 @@ pmap_every_pte_zero(vm_paddr_t pa)
/*
* Tries to create the specified 2MB page mapping. Returns KERN_SUCCESS if
- * the mapping was created, and either KERN_FAILURE or KERN_RESOURCE_SHORTAGE
- * otherwise. Returns KERN_FAILURE if PMAP_ENTER_NOREPLACE was specified and
- * a mapping already exists at the specified virtual address. Returns
- * KERN_RESOURCE_SHORTAGE if PMAP_ENTER_NOSLEEP was specified and a page table
- * page allocation failed. Returns KERN_RESOURCE_SHORTAGE if
- * PMAP_ENTER_NORECLAIM was specified and a PV entry allocation failed.
+ * the mapping was created, and one of KERN_FAILURE, KERN_NO_SPACE,
+ * KERN_PROTECTION_FAILURE, or KERN_RESOURCE_FAILURE otherwise. Returns
+ * KERN_FAILURE if either (1) PMAP_ENTER_NOREPLACE was specified and a 4KB
+ * page mapping already exists within the 2MB virtual address range starting
+ * at the specified virtual address or (2) the requested 2MB page mapping is
+ * not supported due to hardware errata. Returns KERN_NO_SPACE if
+ * PMAP_ENTER_NOREPLACE was specified and a 2MB page mapping already exists at
+ * the specified virtual address. Returns KERN_PROTECTION_FAILURE if the PKRU
+ * settings are not the same across the 2MB virtual address range starting at
+ * the specified virtual address. Returns KERN_RESOURCE_SHORTAGE if either
+ * (1) PMAP_ENTER_NOSLEEP was specified and a page table page allocation
+ * failed or (2) PMAP_ENTER_NORECLAIM was specified and a PV entry allocation
+ * failed.
*
* The parameter "m" is only used when creating a managed, writeable mapping.
*/
@@ -7380,14 +7385,23 @@ pmap_enter_pde(pmap_t pmap, vm_offset_t va, pd_entry_t
newpde, u_int flags,
if ((oldpde & PG_V) != 0) {
KASSERT(pdpg == NULL || pdpg->ref_count > 1,
("pmap_enter_pde: pdpg's reference count is too low"));
- if ((flags & PMAP_ENTER_NOREPLACE) != 0 && (va <
- VM_MAXUSER_ADDRESS || (oldpde & PG_PS) != 0 ||
- !pmap_every_pte_zero(oldpde & PG_FRAME))) {
- if (pdpg != NULL)
- pdpg->ref_count--;
- CTR2(KTR_PMAP, "pmap_enter_pde: failure for va %#lx"
- " in pmap %p", va, pmap);
- return (KERN_FAILURE);
+ if ((flags & PMAP_ENTER_NOREPLACE) != 0) {
+ if ((oldpde & PG_PS) != 0) {
+ if (pdpg != NULL)
+ pdpg->ref_count--;
+ CTR2(KTR_PMAP,
+ "pmap_enter_pde: no space for va %#lx"
+ " in pmap %p", va, pmap);
+ return (KERN_NO_SPACE);
+ } else if (va < VM_MAXUSER_ADDRESS ||
+ !pmap_every_pte_zero(oldpde & PG_FRAME)) {
+ if (pdpg != NULL)
+ pdpg->ref_count--;
+ CTR2(KTR_PMAP,
+ "pmap_enter_pde: failure for va %#lx"
+ " in pmap %p", va, pmap);
+ return (KERN_FAILURE);
+ }
}
/* Break the existing mapping(s). */
SLIST_INIT(&free);
@@ -7482,6 +7496,7 @@ pmap_enter_object(pmap_t pmap, vm_offset_t start,
vm_offset_t end,
vm_offset_t va;
vm_page_t m, mpte;
vm_pindex_t diff, psize;
+ int rv;
VM_OBJECT_ASSERT_LOCKED(m_start->object);
@@ -7494,7 +7509,8 @@ pmap_enter_object(pmap_t pmap, vm_offset_t start,
vm_offset_t end,
va = start + ptoa(diff);
if ((va & PDRMASK) == 0 && va + NBPDR <= end &&
m->psind == 1 && pmap_ps_enabled(pmap) &&
- pmap_enter_2mpage(pmap, va, m, prot, &lock))
+ ((rv = pmap_enter_2mpage(pmap, va, m, prot, &lock)) ==
+ KERN_SUCCESS || rv == KERN_NO_SPACE))
m = &m[NBPDR / PAGE_SIZE - 1];
else
mpte = pmap_enter_quick_locked(pmap, va, m, prot,
diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index dcc0c637cc1e..148e325c84ba 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -4419,13 +4419,12 @@ out:
}
/*
- * Tries to create a read- and/or execute-only 2MB page mapping. Returns true
- * if successful. Returns false if (1) a page table page cannot be allocated
- * without sleeping, (2) a mapping already exists at the specified virtual
- * address, or (3) a PV entry cannot be allocated without reclaiming another
- * PV entry.
+ * Tries to create a read- and/or execute-only 2MB page mapping. Returns
+ * KERN_SUCCESS if the mapping was created. Otherwise, returns an error
+ * value. See pmap_enter_l2() for the possible error values when "no sleep",
+ * "no replace", and "no reclaim" are specified.
*/
-static bool
+static int
pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
struct rwlock **lockp)
{
@@ -4453,8 +4452,7 @@ pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t
m, vm_prot_t prot,
if (pmap != kernel_pmap)
new_l2 |= ATTR_S1_nG;
return (pmap_enter_l2(pmap, va, new_l2, PMAP_ENTER_NOSLEEP |
- PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, m, lockp) ==
- KERN_SUCCESS);
+ PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, m, lockp));
}
/*
@@ -4477,12 +4475,15 @@ pmap_every_pte_zero(vm_paddr_t pa)
/*
* Tries to create the specified 2MB page mapping. Returns KERN_SUCCESS if
- * the mapping was created, and either KERN_FAILURE or KERN_RESOURCE_SHORTAGE
- * otherwise. Returns KERN_FAILURE if PMAP_ENTER_NOREPLACE was specified and
- * a mapping already exists at the specified virtual address. Returns
- * KERN_RESOURCE_SHORTAGE if PMAP_ENTER_NOSLEEP was specified and a page table
- * page allocation failed. Returns KERN_RESOURCE_SHORTAGE if
- * PMAP_ENTER_NORECLAIM was specified and a PV entry allocation failed.
+ * the mapping was created, and one of KERN_FAILURE, KERN_NO_SPACE, or
+ * KERN_RESOURCE_FAILURE otherwise. Returns KERN_FAILURE if
+ * PMAP_ENTER_NOREPLACE was specified and a 4KB page mapping already exists
+ * within the 2MB virtual address range starting at the specified virtual
+ * address. Returns KERN_NO_SPACE if PMAP_ENTER_NOREPLACE was specified and a
+ * 2MB page mapping already exists at the specified virtual address. Returns
+ * KERN_RESOURCE_SHORTAGE if either (1) PMAP_ENTER_NOSLEEP was specified and a
+ * page table page allocation failed or (2) PMAP_ENTER_NORECLAIM was specified
+ * and a PV entry allocation failed.
*/
static int
pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags,
@@ -4509,15 +4510,23 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t
new_l2, u_int flags,
if ((old_l2 = pmap_load(l2)) != 0) {
KASSERT(l2pg == NULL || l2pg->ref_count > 1,
("pmap_enter_l2: l2pg's ref count is too low"));
- if ((flags & PMAP_ENTER_NOREPLACE) != 0 &&
- (!ADDR_IS_KERNEL(va) ||
- (old_l2 & ATTR_DESCR_MASK) == L2_BLOCK ||
- !pmap_every_pte_zero(old_l2 & ~ATTR_MASK))) {
- if (l2pg != NULL)
- l2pg->ref_count--;
- CTR2(KTR_PMAP, "pmap_enter_l2: failure for va %#lx"
- " in pmap %p", va, pmap);
- return (KERN_FAILURE);
+ if ((flags & PMAP_ENTER_NOREPLACE) != 0) {
+ if ((old_l2 & ATTR_DESCR_MASK) == L2_BLOCK) {
+ if (l2pg != NULL)
+ l2pg->ref_count--;
+ CTR2(KTR_PMAP,
+ "pmap_enter_l2: no space for va %#lx"
+ " in pmap %p", va, pmap);
+ return (KERN_NO_SPACE);
+ } else if (!ADDR_IS_KERNEL(va) ||
+ !pmap_every_pte_zero(old_l2 & ~ATTR_MASK)) {
+ if (l2pg != NULL)
+ l2pg->ref_count--;
+ CTR2(KTR_PMAP,
+ "pmap_enter_l2: failure for va %#lx"
+ " in pmap %p", va, pmap);
+ return (KERN_FAILURE);
+ }
}
SLIST_INIT(&free);
if ((old_l2 & ATTR_DESCR_MASK) == L2_BLOCK)
@@ -4617,6 +4626,7 @@ pmap_enter_object(pmap_t pmap, vm_offset_t start,
vm_offset_t end,
vm_offset_t va;
vm_page_t m, mpte;
vm_pindex_t diff, psize;
+ int rv;
VM_OBJECT_ASSERT_LOCKED(m_start->object);
@@ -4629,7 +4639,8 @@ pmap_enter_object(pmap_t pmap, vm_offset_t start,
vm_offset_t end,
va = start + ptoa(diff);
if ((va & L2_OFFSET) == 0 && va + L2_SIZE <= end &&
m->psind == 1 && pmap_ps_enabled(pmap) &&
- pmap_enter_2mpage(pmap, va, m, prot, &lock))
+ ((rv = pmap_enter_2mpage(pmap, va, m, prot, &lock)) ==
+ KERN_SUCCESS || rv == KERN_NO_SPACE))
m = &m[L2_SIZE / PAGE_SIZE - 1];
else
mpte = pmap_enter_quick_locked(pmap, va, m, prot, mpte,
