Re: GLPK memory problem
This is a bit late. On Wed, 4 May 2022, Domingo Alvarez Duarte wrote: You are right about the maximum index is limited by using an 32 bits integer but that doesn't mean that the memory allocation is also limited, we can have several GigaBytes of allocated memory on 64 bits platforms and still have less that 2^32 indices. GLPK's xmalloc and xcalloc each take an int as its parameter. Most ints can represent up to 2**31-1 . Changing their parameters and a small amount of other code would likely enlarge the available memory. It would not solve the indexing issue. xmalloc and xcalloc go through some gyrations to ensure that the memory requested is a multiple of 16. This seems unnessary. The stated reason is already incorporated int malloc and calloc. malloc and calloc return either NULL or a pointer to suitably aligned memory. Even if an odd block is requested, there is no way for the immediately following byte to be allocated. The code likely does little harm. I'd remove it to reduce the code size. -- Michael henne...@web.cs.ndsu.nodak.edu "Sorry but your password must contain an uppercase letter, a number, a haiku, a gang sign, a heiroglyph, and the blood of a virgin." -- someeecards
Re: GLPK memory problem
Hello Andrew ! You are right about the maximum index is limited by using an 32 bits integer but that doesn't mean that the memory allocation is also limited, we can have several GigaBytes of allocated memory on 64 bits platforms and still have less that 2^32 indices. Cheers ! On 4/5/22 16:10, Andrew Makhorin wrote: On Tue, 2022-05-03 at 13:29 +0200, Domingo Alvarez Duarte wrote: Maybe there is a mistake on the previous reply, GLPK is 32/64 bits depending on the compilation/platform/OS on 64 bits operating systems it can allocated more than 4GB of memory. I meant that for indexing arrays glpk routines use variables of type int; since int is a 32-bit quantity even in the LP64 programming model, it is impossible to work with arrays having more than 2^32 elements. Sorry for misunderstanding. Can you use gdb to see how much memory was attempted to allocate ? On 3/5/22 13:11, Andrew Makhorin wrote: On Tue, 2022-05-03 at 06:38 +, Georgios Avgerinopoulos wrote: Hey Community! Just ran into the following problem glp_alloc: no memory available Error detected in file ..\src\env\alloc.c at line 91 We've got plenty of memory (both RAM and hard drive). Any tips? GLPK is a 32-bit software, so the addressing memory is limited to 4 Gb. Best, Georgios +=+ This email is confidential and may be privileged. If you have received it in error, please notify us immediately, delete the email, and do not copy it, disclose its contents or use it for any purpose. +=+
Re: GLPK memory problem
On Tue, 2022-05-03 at 13:29 +0200, Domingo Alvarez Duarte wrote: > Maybe there is a mistake on the previous reply, GLPK is 32/64 bits > depending on the compilation/platform/OS on 64 bits operating systems > it > can allocated more than 4GB of memory. I meant that for indexing arrays glpk routines use variables of type int; since int is a 32-bit quantity even in the LP64 programming model, it is impossible to work with arrays having more than 2^32 elements. Sorry for misunderstanding. > > Can you use gdb to see how much memory was attempted to allocate ? > > > On 3/5/22 13:11, Andrew Makhorin wrote: > > On Tue, 2022-05-03 at 06:38 +, Georgios Avgerinopoulos wrote: > > > Hey Community! > > > > > > Just ran into the following problem > > > > > > > > > > > > glp_alloc: no memory available > > > Error detected in file ..\src\env\alloc.c at line 91 > > > > > > We've got plenty of memory (both RAM and hard drive). > > > > > > Any tips? > > > > GLPK is a 32-bit software, so the addressing memory is limited to 4 > > Gb. > > > > > > > > > > Best, > > > Georgios > > > > > > +=+ > > > This email is confidential and may be privileged. If you have > > > received > > > it in error, please notify us immediately, delete the email, and > > > do > > > not > > > copy it, disclose its contents or use it for any purpose. > > > +=+ > >
Re: GLPK memory problem
Maybe there is a mistake on the previous reply, GLPK is 32/64 bits depending on the compilation/platform/OS on 64 bits operating systems it can allocated more than 4GB of memory. Can you use gdb to see how much memory was attempted to allocate ? On 3/5/22 13:11, Andrew Makhorin wrote: On Tue, 2022-05-03 at 06:38 +, Georgios Avgerinopoulos wrote: Hey Community! Just ran into the following problem glp_alloc: no memory available Error detected in file ..\src\env\alloc.c at line 91 We've got plenty of memory (both RAM and hard drive). Any tips? GLPK is a 32-bit software, so the addressing memory is limited to 4 Gb. Best, Georgios +=+ This email is confidential and may be privileged. If you have received it in error, please notify us immediately, delete the email, and do not copy it, disclose its contents or use it for any purpose. +=+
Re: GLPK memory problem
On Tue, 2022-05-03 at 06:38 +, Georgios Avgerinopoulos wrote: > Hey Community! > > Just ran into the following problem > > > > glp_alloc: no memory available > Error detected in file ..\src\env\alloc.c at line 91 > > We've got plenty of memory (both RAM and hard drive). > > Any tips? GLPK is a 32-bit software, so the addressing memory is limited to 4 Gb. > > Best, > Georgios > > +=+ > This email is confidential and may be privileged. If you have > received > it in error, please notify us immediately, delete the email, and do > not > copy it, disclose its contents or use it for any purpose. > +=+
