Goodness gracious, are we fixing the right problem?
Posted Mar 17, 2012 23:49 UTC (Sat) by giraffedata
In reply to: Goodness gracious, are we fixing the right problem?
Parent article: The trouble with stable pages
you need to delay not just the locked page but also any the depend upon it.
Where such ordering is required, it must be implemented today with write barriers, because otherwise the device driver, not to mention the device, is free to do I/Os from the queue in any order it pleases. But I don't think anyone would be updating a page that is scheduled for I/O and is in front of a write barrier - it would defeat the purpose.
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