lkml.org 
[lkml]   [2007]   [Jul]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: hibernation/snapshot design [was Re: [PATCH] Remove process freezer from suspend to RAM pathway]
On Mon, 9 Jul 2007, Pavel Machek wrote:

>>> Actaully, I'm perfectly fine with that, as long as each task blocked by the
>>> driver due to suspend has PF_FROZEN (or something similar) set. Then, at
>>> least theoretically, we'll be able to drop the freezer from the suspend code
>>> path and move it after device_suspend() (or the hibernation-specific
>>> equivalent) for hibernation (in that case there shouldn't be a problem with
>>> any task waiting on I/O while the freezer is running ;-)).
>>
>> I don't see the need for a freezer for snapshot but that's a different
>> issue. (stop_machine looks good enough to me).
>
> Freezer is not needed for snapshot -- it is needed so that we can
> write out the snapshot to disk without the need for special
> drivers/block/simple-ide-for-suspend.c. (We are doing snapshot, then
> write to disk from userland code in uswsusp).

instead of trying to freeze most of the system, could you do something
like start a virtual machine sandbox to write the data out, and not let
any userspace other then the sandbox operate?

you would need to throw away disk buffers so that you don't mix current
pending I/O with I/O from the sandbox, and this would be a visable change
for how suspend is setup, but wouldn't this work?

David Lang
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-07-09 00:31    [W:0.231 / U:0.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site