kernel_optimize_test/drivers/firewire
Clemens Ladisch 13882a82ee firewire: optimize iso queueing by setting wake only after the last packet
When queueing iso packets, the run time is dominated by the two
MMIO accesses that set the DMA context's wake bit.  Because most
drivers submit packets in batches, we can save much time by
removing all but the last wakeup.

The internal kernel API is changed to require a call to
fw_iso_context_queue_flush() after a batch of queued packets.
The user space API does not change, so one call to
FW_CDEV_IOC_QUEUE_ISO must specify multiple packets to take
advantage of this optimization.

In my measurements, this patch reduces the time needed to queue
fifty skip packets from userspace to one sixth on a 2.5 GHz CPU,
or to one third at 800 MHz.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2011-05-10 22:53:45 +02:00
..
core-card.c firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
core-cdev.c firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
core-device.c firewire: core: ignore link-active bit of new nodes, fix device recognition 2011-03-20 16:45:25 +01:00
core-iso.c firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
core-topology.c firewire: core: fix card->reset_jiffies overflow 2011-01-23 12:31:01 +01:00
core-transaction.c firewire: octlet AT payloads can be stack-allocated 2011-05-10 22:53:44 +02:00
core.h firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
init_ohci1394_dma.c ieee1394: move init_ohci1394_dma to drivers/firewire/ 2010-10-11 14:48:03 +02:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2011-03-21 10:05:22 -07:00
Makefile ieee1394: move init_ohci1394_dma to drivers/firewire/ 2010-10-11 14:48:03 +02:00
net.c firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
nosy-user.h firewire: nosy: endianess fixes and annotations 2010-07-27 11:04:11 +02:00
nosy.c firewire: nosy: char device is not seekable 2010-12-12 15:47:02 +01:00
nosy.h firewire: nosy: misc cleanups 2010-07-27 11:04:10 +02:00
ohci.c firewire: optimize iso queueing by setting wake only after the last packet 2011-05-10 22:53:45 +02:00
ohci.h firewire: ohci: fix TI TSB82AA2 regression since 2.6.35 2010-10-17 14:09:12 +02:00
sbp2.c firewire: sbp2: revert obsolete 'fix stall with "Unsolicited response"' 2011-03-20 16:45:24 +01:00