Size of Vector limited to 1024 MB of Heap Size
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From: Robert A Duff on 24 Jun 2008 16:38 Gene <gene.ressler(a)gmail.com> writes: > Your code thrashes the heap pretty hard. Containers doubles the size > of the vector's internal array each time it runs out. So the 2Gb > request means 1Gb is already in use. Dont' know about your malloc(), > but it's easy to see that a 1Gb allocated block in a 4Gb arena can > preclude a further 2Gb allocation. Good point. Note that when you grow from 1GB to 2GB, you have both allocated for the time it takes to copy the data over. That won't work if the user part of the address space is limited to 3GB. Some part of that 3GB is used for other stuff. Plus the heap might well be fragmented. A better test of how much you can allocate would allocate a whole bunch of smaller objects. - Bob
From: anon on 24 Jun 2008 18:53 Adjust your heap size in the linking phase. In <g3qc68$5a5$1(a)aioe.org>, Dennis Hoppe <dennis.hoppe(a)hoppinet.de> writes: >Hi, > >my machine has 4 GB of RAM and I am wondering, why I can't use >at least 2 or 3 GBytes to run an Ada program. It seems, that my >Ada Compiler (Gnat 4.4.0) limit the memory to 2 GB per default. >Is it possible to allocate more than 2 GB? > >Here is a simple example of an "evil" vector, that gains >more memory in each pass. The program terminates exactly at >1024 MB of used Heap memory. > > >with Ada.Containers.Vectors; > >procedure Heap is > package Generic_Vector is new Ada.Containers.Vectors > (Element_Type => Integer, Index_Type => Natural); > > Evil_Vector : Generic_Vector.Vector; >begin -- Heap > loop > Generic_Vector.Append (Evil_Vector, Integer'Last); > end loop; >end Heap; > > >heap(6374) malloc: *** mmap(size=2147487744) failed (error code=12) >*** error: can't allocate region >*** set a breakpoint in malloc_error_break to debug > >raised STORAGE_ERROR : heap exhausted > > >I could not find a suitable Compiler switch or a parameter, that >can be set for the operating system (linux). "ulimit -v" is already >set to unlimited. > >"gnatmem" reports, that my water mark with 1024 MB is reached, but >the final water mark is, needless to say, higher. > > >Best regards, > Dennis Hoppe
From: Peter Schildmann on 25 Jun 2008 06:39 Dennis Hoppe schrieb: > Here is a simple example of an "evil" vector, that gains > more memory in each pass. The program terminates exactly at > 1024 MB of used Heap memory. I was able to allocate much more memory with the following test program on a 64-bit machine running Debian Etch (tested with gcc 4.1.2 and gcc 4.3.1). - Peter with Ada.Text_IO; with Ada.Containers; with Ada.Containers.Vectors; procedure Heap is subtype Element_Type is Long_Integer; -- 8 bytes Element_Size : constant := Element_Type'Size / Standard'Storage_Unit; subtype Index_Type is Natural range 0 .. 6 * 1024 * 1024 * 1024 / Element_Size - 1; -- 6GB! package Cnt_IO is new Ada.Text_IO.Integer_IO (Ada.Containers.Count_Type); package Generic_Vector is new Ada.Containers.Vectors (Element_Type => Element_Type, Index_Type => Index_Type); Evil_Vector : Generic_Vector.Vector; begin for N in Index_Type'Range loop Generic_Vector.Append (Evil_Vector, Long_Integer (N)); end loop; Ada.Text_IO.Put ("Length: "); Cnt_IO.Put (Generic_Vector.Length (Evil_Vector)); Ada.Text_IO.New_Line; Ada.Text_IO.Put ("Capacity: "); Cnt_IO.Put (Generic_Vector.Capacity (Evil_Vector)); end Heap;
From: Dennis Hoppe on 25 Jun 2008 11:13 Hi Peter, unfortunately, your code provided below produces the same behaviour: heap(9830) malloc: *** mmap(size=2147487744) failed (error code=12) *** error: can't allocate region *** set a breakpoint in malloc_error_break to debug raised STORAGE_ERROR : heap exhausted Another point is, that I run actually a 64 bit OS (Mac OS X 10.5), so I tried to compile the source code explicitly with the 64 bit flag gcc -gnato -m64 -c heap.adb, but I got the following errors: heap.adb:10:04: instantiation error at a-convec.ads:330 heap.adb:10:04: alignment for "Vectort31b" must be at least 8 heap.adb:10:04: instantiation error at a-convec.ads:330 heap.adb:10:04: alignment for "Vectorb36b" must be at least 8 Line 10 is: package Generic_Vector is new Ada.Containers.Vectors (Element_Type => Integer, Index_Type => Natural); Is it possible, that this flag (-m64) is actually not supported for my system/compiler? gcc (GCC) 4.4.0 20080314 (experimental) [trunk revision 133226] GNAT 4.4.0 20080314 (experimental) [trunk revision 133226] Darwin Kernel 9.3.0 root:xnu-1228.5.18~1/RELEASE_I386 i386 Thank you all, Dennis Peter Schildmann wrote: > Dennis Hoppe schrieb: >> loop >> Generic_Vector.Append (Evil_Vector, Integer'Last); >> end loop; > > It's not a good idea to use the STORAGE_ERROR exception > to terminate an endless loop. > > This should work: > > with Ada.Text_IO; > with Ada.Containers; > with Ada.Containers.Vectors; > > procedure Heap is > > package Cnt_IO is new Ada.Text_IO.Integer_IO > (Ada.Containers.Count_Type); > > package Generic_Vector is new Ada.Containers.Vectors > (Element_Type => Integer, Index_Type => Natural); > > Evil_Vector : Generic_Vector.Vector; > > Size : constant := Integer'Size / Standard'Storage_Unit; > > begin > > for N in 0 .. Natural'Last / Size loop > Generic_Vector.Append (Evil_Vector, N); > end loop; > > Cnt_IO.Put (Generic_Vector.Capacity (Evil_Vector)); > > end Heap; > > > - Peter
From: Dennis Hoppe on 25 Jun 2008 11:29
Hi Peter, Peter Schildmann wrote: > I was able to allocate much more memory with the following > test program on a 64-bit machine running Debian Etch > (tested with gcc 4.1.2 and gcc 4.3.1). > [code snippet] The same code runs on machine out of memory at 1024 MB. I thought, my system is 64 bit (Mac OS X 10.5), hmm. With the gcc flag -m64 I get the following error while compiling: heap.adb:17:04: instantiation error at a-convec.ads:330 heap.adb:17:04: alignment for "Vectort31b" must be at least 8 heap.adb:17:04: instantiation error at a-convec.ads:330 heap.adb:17:04: alignment for "Vectorb36b" must be at least 8 Best regards, Dennis |