kern.maxdsiz on amd63 with i386 binaries

Chris Peterson chris at lameness.info
Fri Oct 24 20:55:55 PDT 2008


Hello,

I've got a handful of i386 boxes, and a handful of amd64 boxes running  
a 32-bit application, the reasons for this exact configuration mystify  
me as well as the deployment predates my time in the environment. Now  
that the dataset the application is loading is rapidly approaching  
512MB we're starting to tweak kern.maxdsiz and kern.dfldsiz to 1GB.

The i386 boxes are doing great, but we hit an issue with the amd64  
machines in that 64bit apps seem to work fine, but the 32bit apps  
running on the amd64 machines fail to be able to use more than the  
i386 default of 512MB no matter what we set kern.maxdsiz to. I've also  
tried compiling it into the kernel, which results in the same issue.

I tried starting the app with "limits -d 1090519040", and it seems to  
fail as well. Limits does show the proper value for datasize of  
1064960 kB.

We're locked into 32-bit binaries for this app at the moment thanks to  
some uh... interesting libraries it uses, so the usual option of  
recompile isn't available. I'd like to avoid traveling from San Jose  
to Seattle, then Virginia, then Munich to reinstall the amd64 machines  
with i386 machines if at all possible.

Uh... help?


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