diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2018-08-23 10:45:58 -0600 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2018-08-23 10:45:58 -0600 |
| commit | 154304cd6e99e4222ed762976f9d9aca33c094d3 (patch) | |
| tree | 2741499bcd5a107f249432462447d0afbf7789d1 /migration | |
| parent | 8709b3954d4161bad30ccc435408ec50e10f53cc (diff) | |
postcopy: Synchronize usage of the balloon inhibitor
While the qemu_balloon_inhibit() interface appears rather general purpose,
postcopy uses it in a last-caller-wins approach with no guarantee of balanced
inhibits and de-inhibits. Wrap postcopy's usage of the inhibitor to give it
one vote overall, using the same last-caller-wins approach as previously
implemented at the balloon level.
Fixes: 01ccbec7bdf6 ("balloon: Allow multiple inhibit users")
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/postcopy-ram.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 932f188949..c2e387ed44 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -510,6 +510,20 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis) } /* + * Manage a single vote to the QEMU balloon inhibitor for all postcopy usage, + * last caller wins. + */ +static void postcopy_balloon_inhibit(bool state) +{ + static bool cur_state = false; + + if (state != cur_state) { + qemu_balloon_inhibit(state); + cur_state = state; + } +} + +/* * At the end of a migration where postcopy_ram_incoming_init was called. */ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) @@ -539,7 +553,7 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) mis->have_fault_thread = false; } - qemu_balloon_inhibit(false); + postcopy_balloon_inhibit(false); if (enable_mlock) { if (os_mlock() < 0) { @@ -1107,7 +1121,7 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis) * Ballooning can mark pages as absent while we're postcopying * that would cause false userfaults. */ - qemu_balloon_inhibit(true); + postcopy_balloon_inhibit(true); trace_postcopy_ram_enable_notify(); |