linux/drivers/ieee1394
Nigel Cunningham ec9a13cdbf ieee1394: node manager causes up to ~3.25s delay in freezing tasks
The firewire nodemanager function "nodemgr_host_thread" contains a loop
that calls try_to_freeze near the top of the loop, but then delays for
up to 3.25 seconds (plus time to do work) before getting back to the top
of the loop. When starting a cycle post-boot, this doesn't seem to bite,
but it is causing a noticeable delay at boot time, when freezing
processes prior to starting to read the image.

The following patch adds invocation of try_to_freeze to the subloops
that are used in the body of this function. With these additions, the
time to freeze when starting to resume at boot time is virtually zero.
I'm no expert on firewire, and so don't know that we shouldn't check
the return value and jump back to the top of the loop or such like after
being frozen, but I submit it for your consideration.

Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>

The delay until nodemgr freezes was up to 0.25s (plus time for node
probes) in Linux 2.6.27 and older and up to 3.25s (plus ~) since Linux
2.6.28-rc1, hence much more noticeable.

try_to_freeze() without any jump is correct.  The surrounding code in
the respective loops will catch whether another bus reset happens during
the freeze and handle it.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-12-09 19:34:33 +01:00
..
config_roms.c
config_roms.h
csr1212.c ieee1394: Use DIV_ROUND_UP 2008-10-15 22:21:07 +02:00
csr1212.h
csr.c
csr.h
dma.c
dma.h
dv1394-private.h
dv1394.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2008-11-06 15:55:34 -08:00
dv1394.h
eth1394.c ieee1394: Use DIV_ROUND_UP 2008-10-15 22:21:07 +02:00
eth1394.h
highlevel.c ieee1394: fix list corruption (reported at module removal) 2008-11-29 17:07:56 +01:00
highlevel.h
hosts.c ieee1394: struct device - replace bus_id with dev_name(), dev_set_name() 2008-10-31 08:48:25 +01:00
hosts.h ieee1394: fix list corruption (reported at module removal) 2008-11-29 17:07:56 +01:00
ieee1394_core.c
ieee1394_core.h
ieee1394_hotplug.h
ieee1394_transactions.c
ieee1394_transactions.h
ieee1394_types.h
ieee1394-ioctl.h
ieee1394.h
init_ohci1394_dma.c
iso.c
iso.h
Kconfig
Makefile
nodemgr.c ieee1394: node manager causes up to ~3.25s delay in freezing tasks 2008-12-09 19:34:33 +01:00
nodemgr.h ieee1394: survive a few seconds connection loss 2008-10-15 22:21:09 +02:00
ohci1394.c
ohci1394.h
pcilynx.c
pcilynx.h
raw1394-private.h ieee1394: raw1394: replace BKL by local mutex, make ioctl() and mmap() thread-safe 2008-10-15 22:21:08 +02:00
raw1394.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2008-11-06 15:55:34 -08:00
raw1394.h
sbp2.c ieee1394: sbp2: fix race condition in state change 2008-11-29 17:07:56 +01:00
sbp2.h ieee1394: sbp2: enforce s/g segment size limit 2008-10-15 22:21:07 +02:00
video1394.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2008-10-16 15:02:24 -07:00
video1394.h