[v3,0/4] migration: Fix disorder of channel creations

Message

Peter Xu Feb. 8, 2023, 8:28 p.m. UTC

v3
- Fix indent for uri_supports_multi_channels() [Juan]
- Rename migration_uri_validate() to migration_channels_and_uri_compatible() [Juan]
- Separate the changes to migrate_postcopy_preempt() into separate patch [Juan]

I can trigger disordered connections with preempt mode postcopy (1 out of a
few attemps), which can cause migration to hang during precopy phase, if
e.g. I set the NIC packet loss rate to 50%.

The last patch fixes the real ordering issue.  For each of the patch,
please refer to the commit message and comments in-code.

Any comment welcomed, thanks.

Peter Xu (4):
  migration: Rework multi-channel checks on URI
  migration: Cleanup postcopy_preempt_setup()
  migration: Add a semaphore to count PONGs
  migration: Postpone postcopy preempt channel to be after main

 migration/migration.c    | 122 ++++++++++++++++++++++++++-------------
 migration/migration.h    |  15 ++++-
 migration/multifd.c      |  12 +---
 migration/postcopy-ram.c |  31 +++++-----
 migration/postcopy-ram.h |   4 +-
 migration/savevm.c       |   6 +-
 6 files changed, 118 insertions(+), 72 deletions(-)

Comments

Peter Xu Feb. 8, 2023, 9:03 p.m. UTC | #1

On Wed, Feb 08, 2023 at 03:28:09PM -0500, Peter Xu wrote:
> v3
> - Fix indent for uri_supports_multi_channels() [Juan]
> - Rename migration_uri_validate() to migration_channels_and_uri_compatible() [Juan]
> - Separate the changes to migrate_postcopy_preempt() into separate patch [Juan]

Sorry, Juan, I lost your R-bs on patch 3-4.  They should be exactly the
same as before.