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author | Michael R. Hines <mrhines@us.ibm.com> | 2013-06-25 21:35:36 -0400 |
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committer | Juan Quintela <quintela@redhat.com> | 2013-06-27 02:38:36 +0200 |
commit | 60d9222c8f50c3e5dd3df9ee84ddd1d1c4b35389 (patch) | |
tree | e15ec28f02b7d995171274aa47703244880dd827 /migration.c | |
parent | 43487c678d6e4e7182bfa70d2bc75422578782aa (diff) | |
download | qemu-60d9222c8f50c3e5dd3df9ee84ddd1d1c4b35389.zip qemu-60d9222c8f50c3e5dd3df9ee84ddd1d1c4b35389.tar.gz qemu-60d9222c8f50c3e5dd3df9ee84ddd1d1c4b35389.tar.bz2 |
rdma: introduce capability x-rdma-pin-all
This capability allows you to disable dynamic chunk registration
for better throughput on high-performance links.
For example, using an 8GB RAM virtual machine with all 8GB of memory in
active use and the VM itself is completely idle using a 40 gbps infiniband link:
1. x-rdma-pin-all disabled total time: approximately 7.5 seconds @ 9.5 Gbps
2. x-rdma-pin-all enabled total time: approximately 4 seconds @ 26 Gbps
These numbers would of course scale up to whatever size virtual machine
you have to migrate using RDMA.
Enabling this feature does *not* have any measurable affect on
migration *downtime*. This is because, without this feature, all of the
memory will have already been registered already in advance during
the bulk round and does not need to be re-registered during the successive
iteration rounds.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'migration.c')
-rw-r--r-- | migration.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/migration.c b/migration.c index 441a3b2..a704d48 100644 --- a/migration.c +++ b/migration.c @@ -476,6 +476,15 @@ void qmp_migrate_set_downtime(double value, Error **errp) max_downtime = (uint64_t)value; } +bool migrate_rdma_pin_all(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_X_RDMA_PIN_ALL]; +} + int migrate_use_xbzrle(void) { MigrationState *s; |