preallocate CPU usage - pre4
Rob Bosch
robbosch at msn.com
Mon Nov 5 13:25:05 GMT 2007
When I use the preallocate patch and create a 77GB file using the function I
get a CPU spike on the server-side. The spike lasts about 20 minutes and
uses about 20%-25% of the cpu associated with the rsync instance creating
the file. The spike is directly linked to the time it takes to create the
file.
I compiled rsync using cygwin CVS. I initially suspected the implementation
of posix_fallocate in cygwin. I posted the same question to their board and
Corinna indicated she can create a 40GB file in a few milliseconds. I'm
wondering if there is something else going on at this point.
Does anyone else get this issue too? I want to confirm it isn't just a
problem with my environment. I've replicated it on machines but they are
all using the same cygwin build I created. It would be great to get a
confirmation (positive or negative) from someone running it under Linux.
The preallocate is working, it just is taking a while to create the file.
Rob
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