From e3995aaa436e2ec92e720ff17855c6460dbc3761 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Nigel Croxon Date: Thu, 14 Nov 2013 22:52:47 +0100 Subject: [PATCH 11/46] rdma: introduce capability x-rdma-pin-all RH-Author: Nigel Croxon Message-id: <1384469598-13137-12-git-send-email-ncroxon@redhat.com> Patchwork-id: 55696 O-Subject: [RHEL7.0 PATCH 11/42] rdma: introduce capability x-rdma-pin-all Bugzilla: 1011720 RH-Acked-by: Orit Wasserman RH-Acked-by: Amit Shah RH-Acked-by: Paolo Bonzini Bugzilla: 1011720 https://bugzilla.redhat.com/show_bug.cgi?id=1011720 >From commit ID: commit 60d9222c8f50c3e5dd3df9ee84ddd1d1c4b35389 Author: Michael R. Hines Date: Tue Jun 25 21:35:36 2013 -0400 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 Reviewed-by: Paolo Bonzini Reviewed-by: Chegu Vinod Reviewed-by: Eric Blake Tested-by: Chegu Vinod Tested-by: Michael R. Hines Signed-off-by: Michael R. Hines Signed-off-by: Juan Quintela --- include/migration/migration.h | 1 + migration.c | 9 +++++++++ qapi-schema.json | 7 ++++++- 3 files changed, 16 insertions(+), 1 deletions(-) Signed-off-by: Michal Novotny --- include/migration/migration.h | 1 + migration.c | 9 +++++++++ qapi-schema.json | 7 ++++++- 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index 6455e36..701709a 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -123,6 +123,7 @@ void migrate_add_blocker(Error *reason); */ void migrate_del_blocker(Error *reason); +bool migrate_rdma_pin_all(void); bool migrate_zero_blocks(void); bool migrate_auto_converge(void); diff --git a/migration.c b/migration.c index f4d1e34..73a348f 100644 --- a/migration.c +++ b/migration.c @@ -484,6 +484,15 @@ 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]; +} + bool migrate_auto_converge(void) { MigrationState *s; diff --git a/qapi-schema.json b/qapi-schema.json index 17df327..bf1fe68 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -664,6 +664,11 @@ # This feature allows us to minimize migration traffic for certain work # loads, by sending compressed difference of the pages # +# @x-rdma-pin-all: Controls whether or not the entire VM memory footprint is +# mlock()'d on demand or all at once. Refer to docs/rdma.txt for usage. +# Disabled by default. Experimental: may (or may not) be renamed after +# further testing is complete. (since 1.6) +# # @auto-converge: If enabled, QEMU will automatically throttle down the guest # to speed up convergence of RAM migration. (since 1.6) # @@ -679,7 +684,7 @@ # Since: 1.2 ## { 'enum': 'MigrationCapability', - 'data': ['xbzrle', 'auto-converge', 'zero-blocks'] } + 'data': ['xbzrle', 'x-rdma-pin-all', 'auto-converge', 'zero-blocks'] } ## # @MigrationCapabilityStatus -- 1.7.11.7