[Sorry Chris, resending without the giant attachments.]
Commit 907500095851230a480b14bc852c4e49d32cb16d makes exec migration
much slower than before.
I'm running the latest HEAD of qemu, on Debian Lenny 5.0.2.
I'm migrating a fully booted Linux VM (also running Lenny) with 128MB
of RAM to a file, using the following command: migrate "exec: cat >
vmimage". The resulting file has a size of 57MB (because we save only
what is allocated from the 128MB).
With the current HEAD, it takes from 15 to 40 seconds (it's variable)
to perform the migration to the file.
With commit 907500095851230a480b14bc852c4e49d32cb16d reverted (or just
commenting the "socket_set_nonblock(s->fd);" statement), it takes
about 3 seconds.