Date: Sun, 21 Feb 2010 04:10:25 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r204162 - stable/8/sys/i386/i386 Message-ID: <201002210410.o1L4AP1H012390@svn.freebsd.org>
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Author: alc Date: Sun Feb 21 04:10:25 2010 New Revision: 204162 URL: http://svn.freebsd.org/changeset/base/204162 Log: MFC r203085 Optimize pmap_demote_pde() by using the new KPTmap to access a kernel page table page instead of creating a temporary mapping to it. Set the PG_G bit on the page table entries that implement the KPTmap. Locore initializes the unused portions of the NKPT kernel page table pages that it allocates to zero. So, pmap_bootstrap() needn't zero the page table entries referenced by CMAP1 and CMAP3. Simplify pmap_set_pg(). Modified: stable/8/sys/i386/i386/pmap.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/xen/xenpci/ (props changed) stable/8/sys/netinet/ (props changed) Modified: stable/8/sys/i386/i386/pmap.c ============================================================================== --- stable/8/sys/i386/i386/pmap.c Sun Feb 21 03:49:39 2010 (r204161) +++ stable/8/sys/i386/i386/pmap.c Sun Feb 21 04:10:25 2010 (r204162) @@ -423,7 +423,6 @@ pmap_bootstrap(vm_paddr_t firstaddr) } SYSMAP(caddr_t, CMAP1, CADDR1, 1) SYSMAP(caddr_t, CMAP3, CADDR3, 1) - *CMAP3 = 0; /* * Crashdump maps. @@ -446,7 +445,7 @@ pmap_bootstrap(vm_paddr_t firstaddr) SYSMAP(pt_entry_t *, KPTD, KPTmap, KVA_PAGES) for (i = 0; i < NKPT; i++) - KPTD[i] = (KPTphys + (i << PAGE_SHIFT)) | PG_RW | PG_V; + KPTD[i] = (KPTphys + (i << PAGE_SHIFT)) | pgeflag | PG_RW | PG_V; /* * Adjust the start of the KPTD and KPTmap so that the implementation @@ -458,15 +457,13 @@ pmap_bootstrap(vm_paddr_t firstaddr) /* * ptemap is used for pmap_pte_quick */ - SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1); - SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1); + SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1) + SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1) mtx_init(&PMAP2mutex, "PMAP2", NULL, MTX_DEF); virtual_avail = va; - *CMAP1 = 0; - /* * Leave in place an identity mapping (virt == phys) for the low 1 MB * physical memory region that is used by the ACPI wakeup code. This @@ -539,25 +536,19 @@ pmap_init_pat(void) void pmap_set_pg(void) { - pd_entry_t pdir; pt_entry_t *pte; vm_offset_t va, endva; - int i; if (pgeflag == 0) return; - i = KERNLOAD/NBPDR; endva = KERNBASE + KERNend; if (pseflag) { va = KERNBASE + KERNLOAD; while (va < endva) { - pdir = kernel_pmap->pm_pdir[KPTDI+i]; - pdir |= pgeflag; - kernel_pmap->pm_pdir[KPTDI+i] = PTD[KPTDI+i] = pdir; + pdir_pde(PTD, va) |= pgeflag; invltlb(); /* Play it safe, invltlb() every time */ - i++; va += NBPDR; } } else { @@ -1885,7 +1876,7 @@ pmap_growkernel(vm_offset_t addr) pmap_zero_page(nkpg); ptppaddr = VM_PAGE_TO_PHYS(nkpg); newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M); - pdir_pde(KPTD, kernel_vm_end) = newpdir; + pdir_pde(KPTD, kernel_vm_end) = pgeflag | newpdir; updated_PTD = FALSE; mtx_lock_spin(&allpmaps_lock); @@ -2381,10 +2372,14 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t mptepa = VM_PAGE_TO_PHYS(mpte); /* - * Temporarily map the page table page (mpte) into the kernel's - * address space at either PADDR1 or PADDR2. - */ - if (curthread->td_pinned > 0 && mtx_owned(&vm_page_queue_mtx)) { + * If the page mapping is in the kernel's address space, then the + * KPTmap can provide access to the page table page. Otherwise, + * temporarily map the page table page (mpte) into the kernel's + * address space at either PADDR1 or PADDR2. + */ + if (va >= KERNBASE) + firstpte = &KPTmap[i386_btop(trunc_4mpage(va))]; + else if (curthread->td_pinned > 0 && mtx_owned(&vm_page_queue_mtx)) { if ((*PMAP1 & PG_FRAME) != mptepa) { *PMAP1 = mptepa | PG_RW | PG_V | PG_A | PG_M; #ifdef SMP @@ -2448,10 +2443,9 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t /* * A harmless race exists between this loop and the bcopy() * in pmap_pinit() that initializes the kernel segment of - * the new page table. Specifically, that bcopy() may copy - * the new PDE from the PTD, which is first in allpmaps, to - * the new page table before this loop updates that new - * page table. + * the new page table directory. Specifically, that bcopy() + * may copy the new PDE from the PTD to the new page table + * before this loop updates that new page table. */ mtx_lock_spin(&allpmaps_lock); LIST_FOREACH(allpmaps_entry, &allpmaps, pm_list) {
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