| Message ID | 1494595886-30912-6-git-send-email-a.perevalov@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Alexey Perevalov (a.perevalov@samsung.com) wrote: > Right now it could be used on destination side to > enable vCPU blocktime calculation for postcopy live migration. > vCPU blocktime - it's time since vCPU thread was put into > interruptible sleep, till memory page was copied and thread awake. > > Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > include/migration/migration.h | 1 + > migration/migration.c | 9 +++++++++ > qapi-schema.json | 5 ++++- > 3 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index ba1a16c..82bbcd8 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -315,6 +315,7 @@ int migrate_compress_level(void); > int migrate_compress_threads(void); > int migrate_decompress_threads(void); > bool migrate_use_events(void); > +bool migrate_postcopy_blocktime(void); > > /* Sending on the return path - generic and then for each message type */ > void migrate_send_rp_message(MigrationIncomingState *mis, > diff --git a/migration/migration.c b/migration/migration.c > index 569a7f6..c0443ce 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1371,6 +1371,15 @@ bool migrate_zero_blocks(void) > return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; > } > > +bool migrate_postcopy_blocktime(void) > +{ > + MigrationState *s; > + > + s = migrate_get_current(); > + > + return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME]; > +} > + > bool migrate_use_compression(void) > { > MigrationState *s; > diff --git a/qapi-schema.json b/qapi-schema.json > index 01b087f..fde6d63 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -894,11 +894,14 @@ > # @release-ram: if enabled, qemu will free the migrated ram pages on the source > # during postcopy-ram migration. (since 2.9) > # > +# @postcopy-blocktime: Calculate downtime for postcopy live migration (since 2.10) > +# > # Since: 1.2 > ## > { 'enum': 'MigrationCapability', > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > - 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] } > + 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > + 'postcopy-blocktime'] } > > ## > # @MigrationCapabilityStatus: > -- > 1.9.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 05/12/2017 08:31 AM, Alexey Perevalov wrote: > Right now it could be used on destination side to > enable vCPU blocktime calculation for postcopy live migration. > vCPU blocktime - it's time since vCPU thread was put into > interruptible sleep, till memory page was copied and thread awake. > > Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com> > --- > include/migration/migration.h | 1 + > migration/migration.c | 9 +++++++++ > qapi-schema.json | 5 ++++- > 3 files changed, 14 insertions(+), 1 deletion(-) > > +++ b/qapi-schema.json > @@ -894,11 +894,14 @@ > # @release-ram: if enabled, qemu will free the migrated ram pages on the source > # during postcopy-ram migration. (since 2.9) > # > +# @postcopy-blocktime: Calculate downtime for postcopy live migration (since 2.10) > +# > # Since: 1.2 > ## > { 'enum': 'MigrationCapability', > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > - 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] } > + 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > + 'postcopy-blocktime'] } Why does this need to be a capability that we have to turn on, and not something that is collected unconditionally? Is there a drawback to having the stat collection always enabled without a capability?
On Mon, May 22, 2017 at 11:20:13AM -0500, Eric Blake wrote: > On 05/12/2017 08:31 AM, Alexey Perevalov wrote: > > Right now it could be used on destination side to > > enable vCPU blocktime calculation for postcopy live migration. > > vCPU blocktime - it's time since vCPU thread was put into > > interruptible sleep, till memory page was copied and thread awake. > > > > Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com> > > --- > > include/migration/migration.h | 1 + > > migration/migration.c | 9 +++++++++ > > qapi-schema.json | 5 ++++- > > 3 files changed, 14 insertions(+), 1 deletion(-) > > > > > +++ b/qapi-schema.json > > @@ -894,11 +894,14 @@ > > # @release-ram: if enabled, qemu will free the migrated ram pages on the source > > # during postcopy-ram migration. (since 2.9) > > # > > +# @postcopy-blocktime: Calculate downtime for postcopy live migration (since 2.10) > > +# > > # Since: 1.2 > > ## > > { 'enum': 'MigrationCapability', > > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > > - 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] } > > + 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > > + 'postcopy-blocktime'] } > > Why does this need to be a capability that we have to turn on, and not > something that is collected unconditionally? Is there a drawback to > having the stat collection always enabled without a capability? yes, it has a performance penalty (runtime complexity O(n) + O(m), where n is vCPU number, m is number of memory pages), but not so huge, compared to network latencies, also memory usage, but no more than 0.03% of QEMU's total memory. > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org >
* Eric Blake (eblake@redhat.com) wrote: > On 05/12/2017 08:31 AM, Alexey Perevalov wrote: > > Right now it could be used on destination side to > > enable vCPU blocktime calculation for postcopy live migration. > > vCPU blocktime - it's time since vCPU thread was put into > > interruptible sleep, till memory page was copied and thread awake. > > > > Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com> > > --- > > include/migration/migration.h | 1 + > > migration/migration.c | 9 +++++++++ > > qapi-schema.json | 5 ++++- > > 3 files changed, 14 insertions(+), 1 deletion(-) > > > > > +++ b/qapi-schema.json > > @@ -894,11 +894,14 @@ > > # @release-ram: if enabled, qemu will free the migrated ram pages on the source > > # during postcopy-ram migration. (since 2.9) > > # > > +# @postcopy-blocktime: Calculate downtime for postcopy live migration (since 2.10) > > +# > > # Since: 1.2 > > ## > > { 'enum': 'MigrationCapability', > > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > > - 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] } > > + 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > > + 'postcopy-blocktime'] } > > Why does this need to be a capability that we have to turn on, and not > something that is collected unconditionally? Is there a drawback to > having the stat collection always enabled without a capability? Yes, there was a reasonable CPU/memory overhead. (Although it might be lower now). Dave > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/include/migration/migration.h b/include/migration/migration.h index ba1a16c..82bbcd8 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -315,6 +315,7 @@ int migrate_compress_level(void); int migrate_compress_threads(void); int migrate_decompress_threads(void); bool migrate_use_events(void); +bool migrate_postcopy_blocktime(void); /* Sending on the return path - generic and then for each message type */ void migrate_send_rp_message(MigrationIncomingState *mis, diff --git a/migration/migration.c b/migration/migration.c index 569a7f6..c0443ce 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1371,6 +1371,15 @@ bool migrate_zero_blocks(void) return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; } +bool migrate_postcopy_blocktime(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME]; +} + bool migrate_use_compression(void) { MigrationState *s; diff --git a/qapi-schema.json b/qapi-schema.json index 01b087f..fde6d63 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -894,11 +894,14 @@ # @release-ram: if enabled, qemu will free the migrated ram pages on the source # during postcopy-ram migration. (since 2.9) # +# @postcopy-blocktime: Calculate downtime for postcopy live migration (since 2.10) +# # Since: 1.2 ## { 'enum': 'MigrationCapability', 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', - 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] } + 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', + 'postcopy-blocktime'] } ## # @MigrationCapabilityStatus:
Right now it could be used on destination side to enable vCPU blocktime calculation for postcopy live migration. vCPU blocktime - it's time since vCPU thread was put into interruptible sleep, till memory page was copied and thread awake. Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com> --- include/migration/migration.h | 1 + migration/migration.c | 9 +++++++++ qapi-schema.json | 5 ++++- 3 files changed, 14 insertions(+), 1 deletion(-)