On Mon, Oct 31, 2011 at 6:24 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > On Monday, October 31, 2011, Tejun Heo wrote: >> Commit 27920651fe "PM / Freezer: Make fake_signal_wake_up() wake >> TASK_KILLABLE tasks too" made freezer wake up tasks in TASK_KILLABLE >> sleep too citing non-interruptible but killable sleeps in cifs and >> nfs. >> >> I don't think we can do this. We should not send spurious unsolicited >> non-interruptible wakeups. Most synchornization constructs are built >> to cope with spurious wakeups and any INTERRUPTIBLE sleep must be able >> to handle spurious wakeups but that's not true for KILLABLE sleeps - >> KILLABLE condition cannot be cancelled. >> >> This is probably okay for most cases but circumventing fundamental >> wakeup condition like this is asking for trouble. Furthermore, I'm >> not sure the behavior change brought on by this change - breaking >> nfs/cifs uninterruptible operation guarantee - is correct. If such >> behavior is desirable, the right thing to do is using intr mount >> option, not circumventing it from PM layer. > > Do you have any specific examples of breakage, or is it just that you _think_ > it's not quite right? > > One patch depending on that change has been merged already and I have two > more in the queue, so I'd like to clarify this ASAP. Jeff, Steve? > >> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> >> Cc: Jeff Layton <jlayton@xxxxxxxxxx> >> --- >> Neil, Steve, do the network filesystems need a way to indicate "I can >> either be killed or enter freezer"? Probably, yes, but I will defer to Jeff as he has looked more recently at these issues. I can explain cifs state, and disconnect/reconnection of sessions (and smb2 is a little more feature rich in this regard), but will let Jeff explain the more subtle points you are getting at. -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
