From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3975 invoked by alias); 25 Mar 2002 17:57:29 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 3911 invoked from network); 25 Mar 2002 17:57:27 -0000 Received: from unknown (HELO mailrelay1.lanl.gov) (128.165.4.101) by sources.redhat.com with SMTP; 25 Mar 2002 17:57:27 -0000 Received: from alvie-mail.lanl.gov (localhost.localdomain [127.0.0.1]) by mailrelay1.lanl.gov (8.11.6/8.11.6/(ccn-5)) with ESMTP id g2PHvFp24169; Mon, 25 Mar 2002 10:57:15 -0700 Received: from uiuc.edu (antero.c3.lanl.gov [128.165.20.177]) by alvie-mail.lanl.gov (8.11.6/8.11.6/(ccn-5)) with ESMTP id g2PHvDb12226; Mon, 25 Mar 2002 10:57:13 -0700 Message-ID: <3C9F64F9.6040908@uiuc.edu> Date: Mon, 25 Mar 2002 09:57:00 -0000 From: Scott Pakin Organization: University of Illinois at Urbana-Champaign User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.2-2 i686; en-US; 0.7) Gecko/20010316 X-Accept-Language: en MIME-Version: 1.0 To: Andrew Cagney CC: gdb-patches@sources.redhat.com Subject: Re: PATCH: Make libmmalloc work properly with /dev/zero References: <3C854268.2080508@uiuc.edu> <3C9CDD7A.1080302@cygnus.com> Content-Type: multipart/mixed; boundary="------------050403090002040606050000" X-SW-Source: 2002-03/txt/msg00465.txt.bz2 This is a multi-part message in MIME format. --------------050403090002040606050000 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-length: 515 On 23MAR2002, Andrew Cagney wrote: > Fred's ok with this patch. However, I can't get it to apply - something > ate something while it was in transit? Perhaphs post it as a mime > attachment? Attached. Let me know if that still doesn't work. > I'll also need a ChangeLog entry. 2002-03-05 Scott Pakin * Modified calls to mmap() to make mmap() use MAP_PRIVATE when MDP represents /dev/zero. In all other cases, mmap() continues to use MAP_SHARED. -- Scott --------------050403090002040606050000 Content-Type: text/plain; name="mmap-sup-map_private.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="mmap-sup-map_private.patch" Content-length: 1943 --- mmap-sup.c.ORIG Tue Mar 5 13:53:57 2002 +++ mmap-sup.c Tue Mar 5 14:12:16 2002 @@ -48,6 +48,15 @@ #define PAGE_ALIGN(addr) (caddr_t) (((long)(addr) + pagesize - 1) & \ ~(pagesize - 1)) + +/* Return MAP_PRIVATE if MDP represents /dev/zero. Otherwise, return + MAP_SHARED. */ + +#define MAP_PRIVATE_OR_SHARED(MDP) ((MDP -> flags & MMALLOC_DEVZERO) ? \ + MAP_PRIVATE : \ + MAP_SHARED) + + /* Get core for the memory region specified by MDP, using SIZE as the amount to either add to or subtract from the existing region. Works like sbrk(), but using mmap(). */ @@ -113,7 +122,7 @@ { /* Let mmap pick the map start address */ mapto = mmap (0, mapbytes, PROT_READ | PROT_WRITE, - MAP_SHARED, mdp -> fd, foffset); + MAP_PRIVATE_OR_SHARED(mdp), mdp -> fd, foffset); if (mapto != (caddr_t) -1) { mdp -> base = mdp -> breakval = mapto; @@ -125,7 +134,8 @@ else { mapto = mmap (mdp -> top, mapbytes, PROT_READ | PROT_WRITE, - MAP_SHARED | MAP_FIXED, mdp -> fd, foffset); + MAP_PRIVATE_OR_SHARED(mdp) | MAP_FIXED, mdp -> fd, + foffset); if (mapto == mdp -> top) { mdp -> top = moveto; @@ -152,7 +162,7 @@ /* FIXME: Quick hack, needs error checking and other attention. */ base = mmap (mdp -> base, mdp -> top - mdp -> base, - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, + PROT_READ | PROT_WRITE, MAP_PRIVATE_OR_SHARED(mdp) | MAP_FIXED, mdp -> fd, 0); return ((PTR) base); } @@ -166,13 +176,13 @@ caddr_t base = NULL; #ifdef MAP_ANONYMOUS - flags = MAP_SHARED | MAP_ANONYMOUS; + flags = MAP_PRIVATE | MAP_ANONYMOUS; fd = -1; #else #ifdef MAP_FILE - flags = MAP_SHARED | MAP_FILE; + flags = MAP_PRIVATE | MAP_FILE; #else - flags = MAP_SHARED; + flags = MAP_PRIVATE; #endif fd = open ("/dev/zero", O_RDWR); if (fd != -1) --------------050403090002040606050000--