scsi: lpfc: Fix MRQ > 1 context list handling
Various oops including cpu LOCKUPs were seen. For asynchronously received ius where the driver must assign exchange resources, the resources were on a single get (free) list and put list (finished, waiting to be put on get list). As all cpus are sharing the lists, an interrupt for a receive frame may have to wait for all the other cpus to place their done work onto the put list before it can acquire the lock to pull from the list. Fix by breaking the resource lists into per-cpu lists or at least more than 1 list with cpu's sharing the lists). A cpu would allocate from the free list for its own cpu, and put its done work on the its own put list - avoiding the contention. As cpu load may vary, when empty, a cpu may grab from another cpu, thereby changing resource distribution. But searching for a resource only occurs on 1 or a few cpus until a single resource can be allocated. if the condition reoccurs, it starts looking at a different cpu. Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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