Messages in this thread | | | Date | Wed, 2 Jul 2008 21:52:01 +1000 | From | Bron Gondwana <> | Subject | Re: mmap'ed memory in core files ? |
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On Wed, Jul 02, 2008 at 01:07:22PM +0200, Andi Kleen wrote: > "Rob Mueller" <robm@fastmail.fm> writes: > > > > It's clearly sparse, but slightly unintuitive that the ulimit doesn't > > actually limit the filesize, just the size of the data written to the > > file. > > It's the only sane semantic. Imagine ulimit would limit the address > range as you seem to be asking for. This means if you set e.g. ulimit > -c 1G then the kernel would never dump any address (mmap or not) above > 1GB. Never dumping the process stack for example. Clearly doesn't make > any sense. And mmap'ed files are not different from any other > mappings in this regard.
Hmm.. the IO hit we got with those Cyrus crashes suggested that it was more than just a small amount of IO being caused. I didn't check if the files were sparse or not.
I guess we can probably create a test case that recreates it, even if it's just running up a dodgy Cyrus instance on the machine that had the crashes before and deliberately recreating a broken cache file to trigger it.
Bron.
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