On Wed, 19 Sep 2018, Dmitry Safonov wrote: > On Wed, 2018-09-19 at 13:35 -0400, Mikulas Patocka wrote: > > > > On Wed, 19 Sep 2018, Mikulas Patocka wrote: > > > > > > > > > > > On Tue, 18 Sep 2018, Dmitry Safonov wrote: > > > > > > > Hi all, > > > > > > > > Three fixes that worth to have in the @stable, as they were hit > > by > > > > different people, including Arista on v4.9 stable. > > > > > > > > And for linux-next - adding lockdep asserts for line discipline > > changing > > > > code, verifying that write ldisc sem will be held forthwith. > > > > > > > > The last patch is an optional and probably, timeout can be > > dropped for > > > > read_lock(). I'll do it if everyone agrees. > > > > (Or as per discussion with Peter in v3, just convert ldisc to > > > > a regular rwsem). > > > > > > > > Thanks, > > > > Dima > > > > > > I confirm that this patch series fixes the crash for me. > > > > > > Tested-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > > > > I was too quick to acknowledge this patchset. It doesn't work. > > > > This patchset fixes the crash, but it introduces another bug - when I > > type > > 'reboot' on the console, it prints 'INIT: Switching to runlevel: 6' > > and > > then it gets stuck for 80 seconds before proceeding with the reboot. > > When > > I revert this patchset 'reboot' reboots the machine without any > > delay. > > This bug was reproduced on Debian 5 userspace on pa-risc. > > Thanks much for the testing, Mikulas. > Could you try to bisect which of the patches causes it? > The most important are 1,2,3 - probably, one of them caused it.. > I'll stare a bit into the code. The patch 3 causes it. The hangs during reboot take either 80 seconds, 3 minutes or 3:25. Mikulas
