block-migration: limit the memory usage
commitf77dcdbc76dbf9bade9739e85e1013639e535835
authorWen Congyang <wency@cn.fujitsu.com>
Fri, 20 Nov 2015 09:37:13 +0000 (20 17:37 +0800)
committerJuan Quintela <quintela@redhat.com>
Wed, 25 Nov 2015 14:27:28 +0000 (25 15:27 +0100)
treea9a7e78b4dcca4d788940ef876e1522bf671aad6
parent1d7414396f926651c4d7a673eb3a10aca5246d76
block-migration: limit the memory usage

If we set migration speed in a very large value, block-migration will try to read
all data to the memory. Because
    (block_mig_state.submitted + block_mig_state.read_done) * BLOCK_SIZE
will be overflow, and it will be always less than rate limit.

There is no need to read too many data into memory when the rate limit is very large.
So limit the memory usage can fix the overflow problem.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
migration/block.c