On Monday, February 18, 2013 06:26:34 AM Li, Fei wrote: > > > -----Original Message----- > > From: Rafael J. Wysocki [mailto:r...@sisk.pl] > > Sent: Friday, February 15, 2013 1:38 AM > > To: Miklos Szeredi > > Cc: Pavel Machek; Goswin von Brederlow; Li, Fei; Brown, Len; > > mi...@redhat.com; pet...@infradead.org; Wang, Biao; > > linux...@vger.kernel.org; fuse-de...@lists.sourceforge.net; > > linux-kernel@vger.kernel.org; Liu, Chuansheng > > Subject: Re: Getting rid of freezer for suspend [was Re: [fuse-devel] > > [PATCH] fuse: > > make fuse daemon frozen along with kernel threads] > > > > On Thursday, February 14, 2013 02:09:50 PM Miklos Szeredi wrote: > > > On Thu, Feb 14, 2013 at 1:11 PM, Rafael J. Wysocki <r...@sisk.pl> wrote: > > > > On Thursday, February 14, 2013 11:41:16 AM Miklos Szeredi wrote: > > > > > > >> > > > >> It is essentially the same mechanism that is used to delay the > > > >> freezing of kernel threads after userspace tasks have been frozen. > > > >> Except it's a lot more difficult to determine which userspace tasks > > > >> need to be suspended late and which aren't. > > > > > > > > Well, I suppose that information is available to user space. > > > > > > > > Do we need an interface for a process to mark itself as PF_FREEZE_LATE > > > > or > > > > do we need an interface for one process to mark another process as > > > > PF_FREEZE_LATE, or both? > > > > > > As a first step marking self with PF_FREEZE_LATE and inheriting this > > > flag across fork/clone would work for most cases, I think. > > > > OK, so we can just have a switch for that in /proc I suppose. > > Thanks for feedback and suggestion. > > We have ever tried similar idea, expose interface /sys/power/pm_freeze_daemon, > userspace tasks write 1 to this attribute to make itself to be frozen at the > same time > with kernel tasks, and it worked in our experiment. > > Do you think it's suitable and enough to use such attribute > /sys/power/pm_freeze_late, > or other more suitable place under /proc suggested?
I think it should be inder /proc, because that's where controls related to process behavior are located. E.g. /proc/PID/freeze_late or something like that. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
