On Wed, Apr 19, 2006 at 01:23:56PM +0200, Ketil Malde wrote:
perhaps if -M is not otherwise set, 'getrlimit(RLIMIT_AS,..)' could be called and the maximum heap size set to just under that
Of course, it is commonly set to 'unlimited' anyway. Perhaps I should limit it; OTOH, the value must be less than 2Gb (signed int), which will soon be on the small side for a modern workstation.
on 64 bit systems (where long is 64 bits) it is 64 bits. many 32 bit systems also provide a 'getrlimit64' as part of their long file support which is also 64 bits so I don't forsee this being a big issue in practice.
For my programs, I've found that setting -M to 80% of physical tends to work well. Beyond that, I get thrashing and lousy performance. (Perhaps programs mmap'ing large files etc can work well beyond physical memory? I'd be interested to hear others' experiences.)
yeah, that is what I do, I actually set my ulimit to be about the same to keep any individual thing from getting big enough to swap out my X server and make life unhappy. for the rare app that actually needs > 2G of ram (ahem... jhc) I can temporarily raise the limit. it has made things much nicer when I accidentally write a memory bomb in any language. John -- John Meacham - ⑆repetae.net⑆john⑈