Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [linux-pm] Is it supposed to be ok to call del_gendisk while userspace is frozen? | Date | Fri, 23 Apr 2010 07:17:07 +0200 |
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On Friday 23 April 2010, Matt Reimer wrote: > On Thu, Mar 4, 2010 at 1:15 PM, Pavel Machek <pavel@ucw.cz> wrote: > > Hi! > > > >> > My thought exactly. This is the only approach that also solves the > >> > following race: > >> > > >> > A driver is unloaded at the same time as a suspend starts. > >> > > >> > The writeback thread gets frozen. > >> > > >> > Then before the rmmod thread is frozen, it calls del_gendisk. > >> > > >> > Delaying things by means of a workqueue (or the equivalent) might also > >> > work, but it doesn't seem as safe. For example, some important > >> > writebacks might end up getting delayed until too late. > > > > Delaying writebacks during sleep should be ok... That's why we do > > sync() after userspace is frozen -- nothing really important should be > > waiting for writeback after that point. > > Has this been fixed,
No, it hasn't.
> or has a consensus about how to fix this been > achieved? I'm hitting the same problem and have some time to work on a > fix.
Generally, it looks like del_gendisk should thaw writeback threads, but not during suspend, only during resume.
Rafael
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