Messages in this thread | | | Subject | Re: [patch 0/1] Apply segment size and segment boundary to integrity data | From | "Martin K. Petersen" <> | Date | Tue, 03 Aug 2010 00:44:50 -0400 |
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>>>>> "Christof" == Christof Schmitt <christof.schmitt@de.ibm.com> writes:
Christof> To summarize the limits i see in the zfcp hardware: Christof> - Maximum size of 4k per segment Christof> - The segments must not cross page boundaries Christof> - The number of segments per request is limited
The interesting thing here is that your hw has a limit for the total number of segments whereas other DIX HBAs have separate limits for data and integrity scatterlists.
Christof> What would be the preferred approach for handling the Christof> integrity data limits in the block layer? Introduce new queue Christof> limits for integrity data, or assume that the limits for Christof> integrity data are the same as for user data? I can update my Christof> patch accordingly and include a check for the maximum number Christof> of segments.
I've been messing with this tonight. It's not entirely trivial because of the housekeeping involved, having to accomodate different types of hardware, having to avoid breaking existing setups, and having to work with integrity compiled and without.
My first attempt at this got quite messy. I think I have found a way but it's bedtime here. Give me a day or two to get back to you with something that'll hopefully work for everyone.
-- Martin K. Petersen Oracle Linux Engineering
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