lkml.org 
[lkml]   [2007]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Fw: Re: [mm PATCH 4/6] RCU: (now) CPU hotplug
On Tue, 30 Jan 2007 17:44:47 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> > I need to look at all uses of PF_NOFREEZE -- as I understand the
> > code, processes marked PF_NOFREEZE will continue running, potentially
> > interfering with the hotplug operation. :-(
> >
> > I will pass my findings on to this list.
>
> Well, I did it some time ago, although not very thoroughly.
>
> AFAICS there are not so many, but one that stands out is the worker threads.
> We needed two of them to actually go to sleep, so now it's possible to create
> a "freezeable workqueue" the worker thread of which will not set PF_NOFREEZE,
> but currently this is only used by XFS.

Or we can create a variant of freeze_processes which ignores PF_NOFREEZE.

As I said eariler, we might need to change the freezer code for this
application. In fact we should do so: that sys_sync() call in there is
quite inappropriate, as is, I suppose, the two-pass freeze attempt. As are
the nice printks, come to that.


Pretty simple stuff though.

-
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: 2007-01-30 19:59    [W:0.600 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site