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US 2007/0168626 A1Published application
Transforming flush queue command to memory barrier command in disk drive
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorJorge De Souza
Life of this patent
Estimating the term…
Abstract
In a HDD, the flush queue (cache) command is transformed into a memory barrier command. The HDD thus has an operation mode in which flush commands do not cause the pending commands to be executed immediately, but instead simply introduces a constraint on the command reordering algorithms that prevents commands sent after the flush command from being executed before commands sent prior to the flush command. The constraint may be applied only on write commands.
Claims20
A device for storing data, comprising:
- a data storage medium;
- and
- a controller controlling the medium, the controller executing logic comprising:
- in response to a flush command to flush a command queue, not immediately executing pending commands in the queue and constraining a command reordering algorithm to prevent non-flush commands received after the flush command from being executed prior to commands received before the flush command.
1 more element
A hard disk drive (HDD) comprising:
- means for indicating whether a flush cache feature is active;
- and
- means, responsive for the means for indicating, for sending non-flush commands to a command barrier storage.
A method comprising:
- in the presence of a flush cache command to flush a cache of a HDD, temporarily delaying execution of non-flush cache commands received after the flush cache command is received until commands awaiting execution in the cache and received prior to the flush cache command have been executed.
Dependencies are inferred from the claim text.