• Nigel Cunningham's avatar
    ieee1394: node manager causes up to ~3.25s delay in freezing tasks · ec9a13cd
    Nigel Cunningham authored
    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: default avatarNigel 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: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
    ec9a13cd
nodemgr.c 51.4 KB