lkml.org 
[lkml]   [2008]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2.6.24-git: kmap_atomic() WARN_ON()
On Tue, 26 Feb 2008 21:49:43 +0100 Ingo Molnar <mingo@elte.hu> wrote:

>
> * Andrew Morton <akpm@linux-foundation.org> wrote:
>
> > > This is only being done to satisfy kmap_atomic's requirements, not
> > > libata's.
> > >
> > > I could add a "kmap lock" but that just seems silly.
> > >
> >
> > It's a bit sad to disable interupts across a memset (how big is it?)
> > just for the small proportion of cases which are accessing a highmem
> > page.
> >
> > What you could do is to add an `unsigned long *flags' arg to
> > ata_scsi_rbuf_get() and ata_scsi_rbuf_put(), and then, in
> > ata_scsi_rbuf_get() do
> >
> > if (PageHighmem(page))
> > local_irq_disable(*flags);
>
> it would be much nicer to attach the irq disabling to the object, not to
> some arbitrary place in the code.
>
> i.e. to introduce a kmap_atomic_irqsave(...,flags) and
> kunmap_atomic_irqrestore() API variant. _That_ then could be mapped by
> -rt to a non-irq disabling thing.
>

Sure. But iirc we haven't had a need for this before. Which is a bit odd.



\
 
 \ /
  Last update: 2008-02-26 22:53    [W:0.059 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site