linux/drivers/s390
Julian Wiedmann a87ee11607 s390/qdio: reduce SLSB writes during Input Queue processing
Streamline the processing of QDIO Input Queues, and remove some
intermittent SLSB updates (no deleting of old ACKs, no redundant
transitions through NOT_INIT).

Rather than counting ACKs, we now keep track of the whole batch of
SBALs that were completed during the current polling cycle.
Most completed SBALs stay in their initial state (ie. PRIMED or ERROR),
except that the most recent SBAL in each sub-run is ACKed for
IRQ reduction.

The only logic changes happen in inbound_handle_work(), the other
delta is just a renaming of the variables that track the SBAL batch.

Note that in particular we don't need to flip the _oldest_ SBAL to
an idle state (eg. NOT_INIT or ACKed) as a guard against catching our
own tail. Since get_inbound_buffer_frontier() will never scan more than
the remaining nr_buf_used SBALs, this scenario just doesn't occur.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16 13:44:04 +02:00
..
block s390/dasd: remove ioctl_by_bdev calls 2020-05-21 08:22:20 -06:00
char s390: use fallthrough; 2020-03-25 12:39:37 +01:00
cio s390/qdio: reduce SLSB writes during Input Queue processing 2020-06-16 13:44:04 +02:00
crypto s390/ap: introduce new ap function ap_get_qdev() 2020-05-20 10:22:51 +02:00
net s390 updates for the 5.8 merge window 2020-06-08 12:05:31 -07:00
scsi scsi: zfcp: Move allocation of the shost object to after xconf- and xport-data 2020-05-11 23:19:52 -04:00
virtio virtio/s390: fix race on airq_areas[] 2019-07-26 13:36:18 +02:00
Makefile s390: remove pointless drivers-y in drivers/s390/Makefile 2019-09-16 13:21:51 +02:00