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Re: some processes having large memory footprints

Richard Wohlstadter wrote:

I'm new with the AMD64 debian port and had some questions I'm hoping someone out there can answer for me. One thing I noticed after installing the AMD64 port on our opterons is that some processes seem to have very large memory footprints on the system. For example, sshd instances are taking 26m virtual, bash taking 8m, ntpd taking 11m. Does this have to do with how these binaries are allocating their data structures and since I'm pure 64 bit they suck up more memory? Just seems like alot of waste(although resident memory usage is more in line with what 32bit machines use). Thanks for any input anyone can share regarding this.

It's most likely the program makes a lot of use of pointers. Remember that all pointers are now 64-bit as opposed to 32-bit, so if a program is very pointer heavy it can take close to 2x as much memory. A perl program of mine that builds a gigantic (~5million entry) hash table takes >1.5x as much memory on AMD64 as i386. It's just one of the facts of life about amd64. The thing is, though perl was taking up so much more memory it actually ran a bit faster on my amd64 than a xeon.


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