Date: Sat, 17 Mar 2007 14:10:14 GMT From: Oleksandr Tymoshenko <gonzo@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 116027 for review Message-ID: <200703171410.l2HEAE9U053788@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=116027 Change 116027 by gonzo@gonzo_jeeves on 2007/03/17 14:09:44 o Back to the wonderful world of prefaulting: by clearing write permissions in pmap_enter_quick we ensure that COW will be performed. Suggested by: alc Affected files ... .. //depot/projects/mips2/src/sys/mips/mips/pmap.c#22 edit Differences ... ==== //depot/projects/mips2/src/sys/mips/mips/pmap.c#22 (text+ko) ==== @@ -1334,7 +1334,8 @@ pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot) { - pmap_enter(pmap, va, m, prot, FALSE); + pmap_enter(pmap, va, m, prot & (VM_PROT_READ | VM_PROT_EXECUTE), + FALSE); } /* @@ -1663,11 +1664,14 @@ boolean_t pmap_is_prefaultable(pmap_t pmap, vm_offset_t va) { - /* - * XXX: prefault causes bugs with COW, so let's stick - * with all pages not eligible to prefault. - */ - return (FALSE); + pt_entry_t *pte; + + pte = pmap_pte(pmap, va); + + if ((pte != NULL) && pte_valid(pte)) + return (FALSE); + + return (TRUE); } /*
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