On Thu, 2007-10-18 at 08:04 -0500, Gary Mills wrote:
> Here's a suggestion on the cause:
>
> The root problem seems to be an interaction between Solaris' concept
> of global memory consistency and the fact that Cyrus spawns many
> processes that all memory map (mmap) the same file. Whenever any
> process updates any part of a memory mapped file, Solaris freezes all
> of the processes that have that file mmaped, updates their memory
> tables, and then re-schedules the processes to run. When we have
> problems we see the load average go extremely high and no useful work
> gets done by Cyrus.
that sounds like a somewhat mangled description of the cross-calls done
to invalidate the TLB on other processors when a page is unmapped.
(it certainly doesn't happen on *every* update to a mapped file).
from grepping the source code it looks like cyrus is both multithreaded
and a heavy user of munmap.
- Bill
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