Re: [PATCH] powerpc/rtas: retry when cpu offline races with suspend/migration
From: Nathan Lynch <hidden>
Date: 2019-06-25 18:53:47
From: Nathan Lynch <hidden>
Date: 2019-06-25 18:53:47
Juliet Kim [off-list ref] writes:
There's some concern this could retry forever, resulting in live lock.
First of all the system will make progress in other areas even if there are repeated retries; we're not indefinitely holding locks or anything like that. Second, Linux checks the H_VASI_STATE result on every retry. If the platform wants to terminate the migration (say, if it imposes a timeout), Linux will abandon it when H_VASI_STATE fails to return H_VASI_SUSPENDING. And it seems incorrect to bail out before that happens, absent hard errors on the Linux side such as allocation failures.