Why page-in a SIGKILL-ed process?

Mikhail Teterin mi+kde at aldan.algebra.com
Sat Oct 22 09:20:25 PDT 2005


On Saturday 22 October 2005 08:24 am, Peter Jeremy wrote:
= >17850 mi          1 -16    0  4158M  1118M wdrain 1   0:06  6.10% vim
= >
= >The question is: Why bother with paged-out parts of the process, when
= >it is already doomed by SIGKILL?

= wdrain appears to be associated with file I/O rather than paging
= (though I may be wrong here).  Is it possible that vim had started
= core-dumping before you SIGKILL'd it?  I've seen problems on other
= OS's where core-dumping processes couldn't be killed and caused
= significant performance degradation if they were very large.

Well, indeed, there was a core-dump too. The reason I thought this was
swap-related is because prior to settling on `wdrain', the process was
in `pfault' for a few moments... You are, probably, right -- it was
dumping the vim's core, when I started killing it.

As for the performance degradation during a core-dump, yes, this
definetely is not a FreeBSD-specific problem... Can't this  be
interrupted, though, by SIGKILL-ing the dying process?

Thanks!

	-mi



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