svn commit: r334400 - head/sys/i386/i386

[Konstantin Belousov]

Author: kib
Date: Wed May 30 20:43:48 2018
New Revision: 334400
URL: https://svnweb.freebsd.org/changeset/base/334400

Log:
  Extract code for fast mapping of pte from pmap_extract_and_hold()
  into the helper function pmap_pte_ufast().
  
  Benchmarked by:       bde
  Tested by:    pho
  Sponsored by: The FreeBSD Foundation

Modified:
  head/sys/i386/i386/pmap.c

Modified: head/sys/i386/i386/pmap.c
==============================================================================
--- head/sys/i386/i386/pmap.c   Wed May 30 20:39:22 2018        (r334399)
+++ head/sys/i386/i386/pmap.c   Wed May 30 20:43:48 2018        (r334400)
@@ -1598,6 +1598,26 @@ pmap_pte_quick3(pmap_t pmap, vm_offset_t va)
        return (0);
 }
 
+static pt_entry_t
+pmap_pte_ufast(pmap_t pmap, vm_offset_t va, pd_entry_t pde)
+{
+       pt_entry_t *eh_ptep, pte, *ptep;
+
+       PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+       pde &= PG_FRAME;
+       critical_enter();
+       eh_ptep = (pt_entry_t *)PCPU_GET(pmap_eh_ptep);
+       if ((*eh_ptep & PG_FRAME) != pde) {
+               *eh_ptep = pde | PG_RW | PG_V | PG_A | PG_M;
+               invlcaddr((void *)PCPU_GET(pmap_eh_va));
+       }
+       ptep = (pt_entry_t *)PCPU_GET(pmap_eh_va) + (i386_btop(va) &
+           (NPTEPG - 1));
+       pte = *ptep;
+       critical_exit();
+       return (pte);
+}
+
 /*
  *     Routine:        pmap_extract
  *     Function:
@@ -1637,8 +1657,8 @@ pmap_extract(pmap_t pmap, vm_offset_t va)
 vm_page_t
 pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
 {
-       pd_entry_t pde, newpf;
-       pt_entry_t *eh_ptep, pte, *ptep;
+       pd_entry_t pde;
+       pt_entry_t pte;
        vm_page_t m;
        vm_paddr_t pa;
 
@@ -1658,17 +1678,7 @@ retry:
                                vm_page_hold(m);
                        }
                } else {
-                       newpf = pde & PG_FRAME;
-                       critical_enter();
-                       eh_ptep = (pt_entry_t *)PCPU_GET(pmap_eh_ptep);
-                       if ((*eh_ptep & PG_FRAME) != newpf) {
-                               *eh_ptep = newpf | PG_RW | PG_V | PG_A | PG_M;
-                               invlcaddr((void *)PCPU_GET(pmap_eh_va));
-                       }
-                       ptep = (pt_entry_t *)PCPU_GET(pmap_eh_va) +
-                           (i386_btop(va) & (NPTEPG - 1));
-                       pte = *ptep;
-                       critical_exit();
+                       pte = pmap_pte_ufast(pmap, va, pde);
                        if (pte != 0 &&
                            ((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
                                if (vm_page_pa_tryrelock(pmap, pte & PG_FRAME,
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