X-Spam-Check-By: sourceware.org Date: Fri, 5 Jan 2007 11:52:20 -0600 From: Brian Ford Reply-To: cygwin@cygwin.com To: cygwin@cygwin.com Subject: Re: 1.7.0 CVS mmap failure In-Reply-To: Message-ID: References: <20070105095752.GB28768@calimero.vinschen.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com On Fri, 5 Jan 2007, Brian Ford wrote: > On Fri, 5 Jan 2007, Brian Ford wrote: > > Ok, after further investigation, this is a /3GB boot.ini flag interaction. > > Unfortunately, this is a critical flag for our application, so all our > > machines are configured this way. That is why I failed to realize its > > significance before. > > > > I understand if this is now too much of an obscure case for you to be > > interested in. If so, I'll try to look into it soon on my own. I suspect > > it must have been related to your MEM_TOP_DOWN change. > > One more tidbit before I have time to find the real problem. Compiling > the test case with -Wl,large-address-aware makes the test pass on a /3GB > system. Here is an interesting strace comparison: Non-/3GB: 4978 26688 [main] mmaptest 2284 MapViewNT: 7FFA0000 = NtMapViewOfSection (h:6EC, addr:0, len:28237, off:0, protect:80, type:0) [snip] 60 27113 [main] mmaptest 2284 MapViewNT: 7FFA7000 = NtMapViewOfSection (h:6E8, addr:7FFA7000, len:36864, off:0, protect:80, type:0) 126 27239 [main] mmaptest 2284 mmap64: 0x7FFA0000 = mmap() /3GB not large address aware: 183 22192 [main] mmaptest 2856 MapViewNT: 7FFF0000 = NtMapViewOfSection (h:6F0, addr:0, len:28237, off:0, protect:80, type:0) [snip] 68 22648 [main] mmaptest 2856 MapViewNT: 0 = NtMapViewOfSection (h:6EC, addr:7FFF7000, len:36864, off:0, protect:80, type:0) 44 22692 [main] mmaptest 2856 seterrno_from_win_error: ../../../../cygwin/winsup/cygwin/mmap.cc:1707 windows error 487 46 22738 [main] mmaptest 2856 geterrno_from_win_error: windows error 487 == errno 22 41 22779 [main] mmaptest 2856 __set_errno: void seterrno_from_win_error(const char*, int, DWORD):310 val 22 79 22858 [main] mmaptest 2856 __set_errno: void* mmap64(void*, size_t, int, int, int, _off64_t):1251 val 12 --- Process 2856, exception C0000008 at 7C90EB74 13337 36195 [main] mmaptest 2856 mmap64: 0xFFFFFFFF = mmap() /3GB large address aware: 191 22246 [main] mmaptest 3420 MapViewNT: AEFA0000 = NtMapViewOfSection (h:6EC, addr:0, len:28237, off:0, protect:80, type:0) [snip] 66 22676 [main] mmaptest 3420 MapViewNT: AEFA7000 = NtMapViewOfSection (h:6E8, addr:AEFA7000, len:36864, off:0, protect:80, type:0) 126 22802 [main] mmaptest 3420 mmap64: 0xAEFA0000 = mmap() The second MapViewNT call is filling out the padding to a 64k boundary. It appears in the problem case that the system doesn't like the 0x7FFF7000 address. Any idea why? -- Brian Ford Lead Realtime Software Engineer VITAL - Visual Simulation Systems FlightSafety International the best safety device in any aircraft is a well-trained crew... -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/