lkml.org 
[lkml]   [2007]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 03/29] mm: allow PF_MEMALLOC from softirq context
From
Date
On Thu, 2007-02-22 at 10:16 +0100, Peter Zijlstra wrote:
> On Wed, 2007-02-21 at 16:53 +0100, Arjan van de Ven wrote:
> > > Index: linux-2.6-git/kernel/softirq.c
> > > ===================================================================
> > > --- linux-2.6-git.orig/kernel/softirq.c 2006-12-14 10:02:18.000000000 +0100
> > > +++ linux-2.6-git/kernel/softirq.c 2006-12-14 10:02:52.000000000 +0100
> > > @@ -209,6 +209,8 @@ asmlinkage void __do_softirq(void)
> > > __u32 pending;
> > > int max_restart = MAX_SOFTIRQ_RESTART;
> > > int cpu;
> > > + unsigned long pflags = current->flags;
> > > + current->flags &= ~PF_MEMALLOC;
> > >
> > > pending = local_softirq_pending();
> > > account_system_vtime(current);
> > > @@ -247,6 +249,7 @@ restart:
> > >
> > > account_system_vtime(current);
> > > _local_bh_enable();
> > > + current->flags = pflags;
> >
> > this wipes out all the flags in one go.... evil.
> > What if something just selected this process for OOM killing? you nuke
> > that flag here again. Would be nicer if only the PF_MEMALLOC bit got
> > inherited in the restore path..
>
> would something like this:
>
> #define PF_PUSH(tsk, pflags, mask) \
> do { \
> (pflags) = ((tsk)->flags) & (mask); \
> } while (0)
>
>
> #define PF_POP(tsk, pflags, mask) \
> do { \
> ((tsk)->flags &= ~(mask); \
> ((tsk)->flags |= (pflags); \
> } while (0)
>
> be useful, or shall I just open code it in various places?

technically all you need is __get_bit and __set_bit() right?
(well a set_bit which sets to a value, not to always-1)

more generic name at least ;)

--
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

-
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: 2007-02-22 10:51    [W:0.259 / U:0.320 seconds]
©2003-2014 Jasper Spaans. Advertise on this site