Process size increased to 90% in 64-bit servers

[Thiagu_1]

We migrated our application from 32-bit to 64-bit UNIX servers. Our application runs on Sun Solaris 5.9, HP-UX 11i v1&v2 PA-RISC, HP-UX 11.23 ipf64.

In 32-bit mode, one our process size was around 100MB while in 64-bit mdoe it increased to 190MB (90% increase of previous size). We know that the process size would obviously increase for 64-bit servers.

Could you suggest us any guidelines or in which areas we need to look out so that to reduce our process size?

[Dennis Handly]

I assume that you are only measuring the process data size and not text?

If your process size was 100 Mb and you have no expectation that it will grow 10 times larger, you should not have converted to 64 bit, at least on HP-UX.

Of course if you are using shared memory and share with another larger process, you are locked in.

One increase in memory would be due to larger pointer and long sizes. So if the majority of your data are these types, it would be expected to get that large of an increase.

If you don't need 64 bit values, you may want to use int32_t for your data types, instead of long.

Other areas of analysis you can do is to print sizeof on all of your classes and structs to see if there are any obvious increases for those classes that have lots of instances in the heap.