lkml.org 
[lkml]   [2010]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/2] drivers/isdn/hardware/mISDN: Use GFP_ATOMIC when a lock is held
On Tue, 1 Jun 2010, Karsten Keil wrote:

> Hello Julia,
>
> thanks for that report, the issue is valid, but I think the fix in that case
> should be to move the allocation to an other place, to avoid wasting of
> GFP_ATOMIC allocation. I will come up with an other fix.

OK, thanks. It's not so easy to see what to do in the interprocedural
case.

julia

> Karsten
>
>
> On Sun, May 30, 2010 at 03:49:40PM +0200, Julia Lawall wrote:
> > From: Julia Lawall <julia@diku.dk>
> >
> > The function inittiger is only called from nj_init_card, where a lock is held.
> >
> > The semantic patch that makes this change is as follows:
> > (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @gfp exists@
> > identifier fn;
> > position p;
> > @@
> >
> > fn(...) {
> > ... when != spin_unlock_irqrestore
> > when any
> > GFP_KERNEL@p
> > ... when any
> > }
> >
> > @locked@
> > identifier gfp.fn;
> > @@
> >
> > spin_lock_irqsave(...)
> > ... when != spin_unlock_irqrestore
> > fn(...)
> >
> > @depends on locked@
> > position gfp.p;
> > @@
> >
> > - GFP_KERNEL@p
> > + GFP_ATOMIC
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> >
> > ---
> > drivers/isdn/hardware/mISDN/netjet.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff -u -p a/drivers/isdn/hardware/mISDN/netjet.c b/drivers/isdn/hardware/mISDN/netjet.c
> > --- a/drivers/isdn/hardware/mISDN/netjet.c
> > +++ b/drivers/isdn/hardware/mISDN/netjet.c
> > @@ -320,12 +320,12 @@ inittiger(struct tiger_hw *card)
> > return -ENOMEM;
> > }
> > for (i = 0; i < 2; i++) {
> > - card->bc[i].hsbuf = kmalloc(NJ_DMA_TXSIZE, GFP_KERNEL);
> > + card->bc[i].hsbuf = kmalloc(NJ_DMA_TXSIZE, GFP_ATOMIC);
> > if (!card->bc[i].hsbuf) {
> > pr_info("%s: no B%d send buffer\n", card->name, i + 1);
> > return -ENOMEM;
> > }
> > - card->bc[i].hrbuf = kmalloc(NJ_DMA_RXSIZE, GFP_KERNEL);
> > + card->bc[i].hrbuf = kmalloc(NJ_DMA_RXSIZE, GFP_ATOMIC);
> > if (!card->bc[i].hrbuf) {
> > pr_info("%s: no B%d recv buffer\n", card->name, i + 1);
> > return -ENOMEM;
> > --
> > To unsubscribe from this list: send the line "unsubscribe netdev" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>


\
 
 \ /
  Last update: 2010-06-01 10:17    [W:0.047 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site