Date: Sat, 17 May 2014 14:35:18 +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-10@freebsd.org Subject: svn commit: r266315 - stable/10/sys/vm Message-ID: <201405171435.s4HEZIHp051310@svn.freebsd.org>
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Author: alc Date: Sat May 17 14:35:18 2014 New Revision: 266315 URL: http://svnweb.freebsd.org/changeset/base/266315 Log: MFC r265850 About 9% of the pmap_protect() calls being performed by vm_map_copy_entry() are unnecessary. Eliminate the unnecessary calls. Modified: stable/10/sys/vm/vm_map.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/vm/vm_map.c ============================================================================== --- stable/10/sys/vm/vm_map.c Sat May 17 14:22:37 2014 (r266314) +++ stable/10/sys/vm/vm_map.c Sat May 17 14:35:18 2014 (r266315) @@ -3023,7 +3023,8 @@ vm_map_copy_entry( * If the source entry is marked needs_copy, it is already * write-protected. */ - if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { + if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && + (src_entry->protection & VM_PROT_WRITE) != 0) { pmap_protect(src_map->pmap, src_entry->start, src_entry->end,
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