On Wed Jul 19, 2006 at 17:48:49 +1000, Carlo Sogono wrote: >Thank you for your reply. See below for comments. > >Erik de Castro Lopo wrote: >>Carlo Sogono wrote: >> >>>Does RHEL or Linux in general limit the amount of memory being used by a >>>single process? >> >>All linux systems limit the amount to memory to be less than >>the totla virtual memory of the system :-). > >I understand that, but my question was with regards to a *single* >process, or will each process just share whatever memory is left? > >> >>>In the first maybe 5 million mallocs it can do >>>about 100,000 mallocs per second, however after more than 1 GB worth it >>>slows down to just a few thousand per second. >> >>How much virtual and real memory do you actually have? > >We have 9GB of physical memory. At the moment, my application has to be >able to comfortably handle 4GB of memory handled by just *one* process.
There is a conflation of terms here. Virtual memory generally refers to the size of the address space of a process. Not how much swap space you have which is a seperate thing. On a 32-bit system, the largest virtual address space a process can have is 4GB, except the kernel will use the top 1 or 2GB of your virtual address space. If you are on a 64-bit system then you will probably have at least 2^40 bits of address space. Basically, if you are running on a 32-bit processor and you need 4GB of virtual memory in one process you are pretty much screwed. (There might be some l33t kernel patches for a so called 4/4 system around which means you need to address space switchevery time you enter the kernel for a system call.. pretty expensive.) Hope that helps. Benno _______________________________________________ coders mailing list [email protected] http://lists.slug.org.au/listinfo/coders
