On 28.10.21 22:16, Marek Marczykowski-Górecki wrote:
On Thu, Oct 28, 2021 at 12:59:52PM +0200, Juergen Gross wrote:When running as PVH or HVM guest with actual memory < max memory the hypervisor is using "populate on demand" in order to allow the guest to balloon down from its maximum memory size. For this to work correctly the guest must not touch more memory pages than its target memory size as otherwise the PoD cache will be exhausted and the guest is crashed as a result of that. In extreme cases ballooning down might not be finished today before the init process is started, which can consume lots of memory. In order to avoid random boot crashes in such cases, add a late init call to wait for ballooning down having finished for PVH/HVM guests. Cc: <stable@xxxxxxxxxxxxxxx> Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>It may happen that initial balloon down fails (state==BP_ECANCELED). In that case, it waits indefinitely. I think it should rather report a failure (and panic? it's similar to OOM before PID 1 starts, so rather hard to recover), instead of hanging.
Okay, I can add something like that. I'm thinking of issuing a failure message in case of credit not having changed for 1 minute and panic() after two more minutes. Is this fine? Juergen
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