Messages in this thread | | | Date | Wed, 22 Jul 2015 01:00:10 +0200 | Subject | Re: [PATCH v2 1/3] PM suspend/hibernate: Call notifier after freezing processes | From | "Rafael J. Wysocki" <> |
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Hi Neil,
On Wed, Jul 22, 2015 at 12:08 AM, NeilBrown <neilb@suse.com> wrote: > On Mon, 20 Jul 2015 23:46:32 +0200 "Rafael J. Wysocki" > <rjw@rjwysocki.net> wrote: > >> On Monday, July 20, 2015 09:32:26 AM Pali Rohár wrote: >> > On Saturday 18 July 2015 01:27:15 Rafael J. Wysocki wrote: >> > > On Thursday, July 16, 2015 09:33:02 AM Pali Rohár wrote: >> > > > On Thursday 16 July 2015 03:02:03 Rafael J. Wysocki wrote: >> > > > > Also, if you're adding AFTER_FREEZE, it would be good to add BEFORE_THAW too >> > > > > for symmetry. >> > > > > >> > > > >> > > > But there is no use case for BEFORE_THAW. At least it is not needed for now. >> > > >> > > For your use case, a single function pointer would be sufficient too. >> > > >> > >> > What do you mean by single function pointer? kernel/power is part of >> > kernel image and dm-crypt is external kernel module. >> >> Well, if there is a function pointer in the core suspend code initially set to >> NULL and exported to modules such that the dm-crypt code can set it to >> something else, that should be sufficient, shouldn't it? > > As long as the dm-crypt module is never unloaded.
OK, there is a race related to that.
> And as long as no other module could very possible want functionality like this. Ever.
The point was that there were no other users currently, so dm-crypt is going to be the only user for the time being.
> If a module wants to be notified - the providing a notifier chain > really seems like the right thing to do...
Well, so please see my last response in this thread. :-)
Thanks, Rafael
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