Messages in this thread | | | From | "Luck, Tony" <> | Date | Wed, 28 Sep 2011 15:30:04 -0700 | Subject | RE: [RFC][PATCH -next] pstore: replace spin_lock with spin_trylock_irqsave in panic path |
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> That should be up to the backend, no? ERST has two modes, only one which > has a state machine. The other is NVRAM which can probably handle > simultaneous writes. And I believe the EFI back-end can handle that as > well. That is why I was suggesting that the back-end return a failure.
ERST tries to provide a lot of flexibility to the platform on how to make persistent space available. If the platform has directly addressable NVRAM - then ERST can point to it, so the "save" operation degenerates into a simple write to the next available block. But this isn't required. The ERST buffer may be in normal memory, and the actions in the state machine may trigger an SMI to make the BIOS copy it away to some safe place, or the actions could ping a doorbell on a management controller which could initiate a DMA transfer to pick up the buffer from memory.
-Tony
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