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diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -1495,6 +1495,16 @@
pmap->pm_stats.resident_count += count;
}
+static __inline void
+pmap_pt_page_count_pinit(pmap_t pmap, int count)
+{
+ KASSERT(pmap->pm_stats.resident_count + count >= 0,
+ ("pmap %p resident count underflow %ld %d", pmap,
+ pmap->pm_stats.resident_count, count));
+ pmap->pm_stats.resident_count += count;
+ counter_u64_add(user_pt_page_count, count);
+}
+
static __inline void
pmap_pt_page_count_adj(pmap_t pmap, int count)
{
@@ -4344,13 +4354,24 @@
vm_paddr_t pmltop_phys;
int i;
+ bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
+
/*
- * Allocate the page directory page. Pass NULL instead of a pointer to
- * the pmap here to avoid recording this page in the resident count, as
- * optimizations in pmap_remove() depend on this.
+ * Allocate the page directory page. Pass NULL instead of a
+ * pointer to the pmap here to avoid calling
+ * pmap_resident_count_adj() through pmap_pt_page_count_adj(),
+ * since that requires pmap lock. Instead do the accounting
+ * manually.
+ *
+ * Note that final call to pmap_remove() optimization that
+ * checks for zero resident_count is basically disabled by
+ * accounting for top-level page. But the optimization was
+ * not effective since we started using non-managed mapping of
+ * the shared page.
*/
pmltop_pg = pmap_alloc_pt_page(NULL, 0, VM_ALLOC_WIRED | VM_ALLOC_ZERO |
VM_ALLOC_WAITOK);
+ pmap_pt_page_count_pinit(pmap, 1);
pmltop_phys = VM_PAGE_TO_PHYS(pmltop_pg);
pmap->pm_pmltop = (pml5_entry_t *)PHYS_TO_DMAP(pmltop_phys);
@@ -4380,11 +4401,13 @@
pmap_pinit_pml4(pmltop_pg);
if ((curproc->p_md.md_flags & P_MD_KPTI) != 0) {
/*
- * As with pmltop_pg, pass NULL instead of a pointer to
- * the pmap to ensure that the PTI page isn't counted.
+ * As with pmltop_pg, pass NULL instead of a
+ * pointer to the pmap to ensure that the PTI
+ * page counted explicitly.
*/
pmltop_pgu = pmap_alloc_pt_page(NULL, 0,
VM_ALLOC_WIRED | VM_ALLOC_WAITOK);
+ pmap_pt_page_count_pinit(pmap, 1);
pmap->pm_pmltopu = (pml4_entry_t *)PHYS_TO_DMAP(
VM_PAGE_TO_PHYS(pmltop_pgu));
if (pmap_is_la57(pmap))
@@ -4407,7 +4430,6 @@
vm_radix_init(&pmap->pm_root);
CPU_ZERO(&pmap->pm_active);
TAILQ_INIT(&pmap->pm_pvchunk);
- bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
pmap->pm_flags = flags;
pmap->pm_eptgen = 0;
@@ -4799,9 +4821,6 @@
vm_page_t m;
int i;
- KASSERT(pmap->pm_stats.resident_count == 0,
- ("pmap_release: pmap %p resident count %ld != 0",
- pmap, pmap->pm_stats.resident_count));
KASSERT(vm_radix_is_empty(&pmap->pm_root),
("pmap_release: pmap %p has reserved page table page(s)",
pmap));
@@ -4834,15 +4853,21 @@
}
pmap_free_pt_page(NULL, m, true);
+ pmap_pt_page_count_pinit(pmap, -1);
if (pmap->pm_pmltopu != NULL) {
m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pmap->
pm_pmltopu));
pmap_free_pt_page(NULL, m, false);
+ pmap_pt_page_count_pinit(pmap, -1);
}
if (pmap->pm_type == PT_X86 &&
(cpu_stdext_feature2 & CPUID_STDEXT2_PKU) != 0)
rangeset_fini(&pmap->pm_pkru);
+
+ KASSERT(pmap->pm_stats.resident_count == 0,
+ ("pmap_release: pmap %p resident count %ld != 0",
+ pmap, pmap->pm_stats.resident_count));
}
static int

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