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Fix a serious problem that manifested during swap, and a few other times.

Browse Source 
pmap_remove() would be called with a huge range and we'd stride across
it in only 2MB chunks.  This would manifest as massive cpu time and a
largely unresponsive system during hard swap.  Instead, check the higher
page directories which means we can run pmap_remove() in just a few
hundred loop iterations instead of millions since we can process
address space in chunks of 512GB and 1GB as well as 2MB.

Eternal thanks to:  tmm
This commit is contained in:
peter 2004-06-07 23:51:20 +00:00
parent 101e49d30a
commit 33636f4f34
1 changed files with 60 additions and 18 deletions
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78
sys/amd64/amd64/pmap.c
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@ -1561,7 +1561,9 @@ pmap_remove_page(pmap_t pmap, vm_offset_t va)
void
pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
vm_offset_t pdnxt;
vm_offset_t va_next;
pml4_entry_t *pml4e;
pdp_entry_t *pdpe;
pd_entry_t ptpaddr, *pde;
pt_entry_t *pte;
int anyvalid;
@ -1587,15 +1589,27 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
anyvalid = 0;
for (; sva < eva; sva = pdnxt) {
for (; sva < eva; sva = va_next) {
if (pmap->pm_stats.resident_count == 0)
break;
pml4e = pmap_pml4e(pmap, sva);
if (pml4e == 0) {
va_next = (sva + NBPML4) & ~PML4MASK;
continue;
}
pdpe = pmap_pdpe(pmap, sva);
if (pdpe == 0) {
va_next = (sva + NBPDP) & ~PDPMASK;
continue;
}
/*
* Calculate index for next page table.
*/
pdnxt = (sva + NBPDR) & ~PDRMASK;
va_next = (sva + NBPDR) & ~PDRMASK;
pde = pmap_pde(pmap, sva);
if (pde == 0)
@ -1624,10 +1638,10 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
* by the current page table page, or to the end of the
* range being removed.
*/
if (pdnxt > eva)
pdnxt = eva;
if (va_next > eva)
va_next = eva;
for (; sva != pdnxt; sva += PAGE_SIZE) {
for (; sva != va_next; sva += PAGE_SIZE) {
pte = pmap_pte(pmap, sva);
if (pte == NULL || *pte == 0)
continue;
@ -1713,7 +1727,9 @@ pmap_remove_all(vm_page_t m)
void
pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
{
vm_offset_t pdnxt;
vm_offset_t va_next;
pml4_entry_t *pml4e;
pdp_entry_t *pdpe;
pd_entry_t ptpaddr, *pde;
int anychanged;
@ -1730,9 +1746,21 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
anychanged = 0;
for (; sva < eva; sva = pdnxt) {
for (; sva < eva; sva = va_next) {
pdnxt = (sva + NBPDR) & ~PDRMASK;
pml4e = pmap_pml4e(pmap, sva);
if (pml4e == 0) {
va_next = (sva + NBPML4) & ~PML4MASK;
continue;
}
pdpe = pmap_pdpe(pmap, sva);
if (pdpe == 0) {
va_next = (sva + NBPDP) & ~PDPMASK;
continue;
}
va_next = (sva + NBPDR) & ~PDRMASK;
pde = pmap_pde(pmap, sva);
if (pde == NULL)
@ -1756,10 +1784,10 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
continue;
}
if (pdnxt > eva)
pdnxt = eva;
if (va_next > eva)
va_next = eva;
for (; sva != pdnxt; sva += PAGE_SIZE) {
for (; sva != va_next; sva += PAGE_SIZE) {
pt_entry_t pbits;
pt_entry_t *pte;
vm_page_t m;
@ -2195,7 +2223,7 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
{
vm_offset_t addr;
vm_offset_t end_addr = src_addr + len;
vm_offset_t pdnxt;
vm_offset_t va_next;
vm_page_t m;
if (dst_addr != src_addr)
@ -2204,9 +2232,11 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
if (!pmap_is_current(src_pmap))
return;
for (addr = src_addr; addr < end_addr; addr = pdnxt) {
for (addr = src_addr; addr < end_addr; addr = va_next) {
pt_entry_t *src_pte, *dst_pte;
vm_page_t dstmpte, srcmpte;
pml4_entry_t *pml4e;
pdp_entry_t *pdpe;
pd_entry_t srcptepaddr, *pde;
vm_pindex_t ptepindex;
@ -2222,7 +2252,19 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
pv_entry_count > pv_entry_high_water)
break;
pdnxt = (addr + NBPDR) & ~PDRMASK;
pml4e = pmap_pml4e(src_pmap, addr);
if (pml4e == 0) {
va_next = (addr + NBPML4) & ~PML4MASK;
continue;
}
pdpe = pmap_pdpe(src_pmap, addr);
if (pdpe == 0) {
va_next = (addr + NBPDP) & ~PDPMASK;
continue;
}
va_next = (addr + NBPDR) & ~PDRMASK;
ptepindex = pmap_pde_pindex(addr);
pde = pmap_pde(src_pmap, addr);
@ -2254,11 +2296,11 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
if (srcmpte->hold_count == 0 || (srcmpte->flags & PG_BUSY))
continue;
if (pdnxt > end_addr)
pdnxt = end_addr;
if (va_next > end_addr)
va_next = end_addr;
src_pte = vtopte(addr);
while (addr < pdnxt) {
while (addr < va_next) {
pt_entry_t ptetemp;
ptetemp = *src_pte;
/*