Linux VM limits
 

I am trying to do a continuous malloc() to allocate as much memory I can. But After allocating nearly 3G , malloc() returns ENOMEM. But I can see a lot of memory still available(By top).
I am using 2.6.x kernel on a 32 bit x86 box. Is it the 32-bit limit?. ulimit gives me 'unlimited' in both max memory size and virtual memory.
Is there anyway I can increase this limit? (by /proc or something)

Hope its there... If not Linux being a monolithic guy is not doing good on monolithic applications..

Thanks and Regards

In 32-bit mode, Linux limits user virtual memory to 3GB/process. In 32-bit PAE mode, the limit is 64GB. In x86_64 (64-bit) the limit is about 8 million TB.

I don't understand the "monolithic" reference, as this is an application design issue, and the kernel structure has no bearing on a virtual memory discussion.

Thanks macemoneta !!!

I mentioned 'monolithic' is just in a architecture sense.One process doing everything requires more memory ... thats why

I suggest you study up on that some more. Compare memory utilizations across kernel architectures, and you will find that a monolithic kernel is difficult to get correct... but it is also the most efficient. No message passing (which requires memory), no coordination data structures (which require memory).