On Sun, Mar 23, 2008 at 11:35 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote:
> On Sun, Mar 23, 2008 at 7:01 PM, Robert P. J. Day <rpjday@xxxxxxxxxxxxxx> wrote:
> > On Sun, 23 Mar 2008, Manish Katiyar wrote:
> >
> > ... snip ...
> >
> >
> > > > list_splice(&d->fifo_list, &packet_list);
> > > > list_splice(&d->pending_list, &packet_list);
> > > > INIT_LIST_HEAD(&d->fifo_list);
> > > > INIT_LIST_HEAD(&d->pending_list);
> > > > ...
> > >
> > > Interesting point Robert, I agree. However not every call to
> > > list_splice is accompanied by a call to INIT_LIST_HEAD in the
> > > current code (26.24.2) and I can see this *seem to be buggy* call in
> > > some of the important files like VM and cache. One such example is
> > > in
> > >
> > > kmem_cache_shrink
> > > shrink_page_list
> > >
> > > etc. and lot of others. Wonder how they work unless we are missing
> > > something :-)
> >
> > by the way, in some cases, there is a call to INIT_LIST_HEAD but it
> > might be a number of lines down in the code so sometimes it's not
> > obvious. i've noticed a couple of those.
> >
>
> Hmmm.... after seeing the list_del(), I was wondering if after
> splicing the list, what seems to be more reasonable.
>
> Setting the prev and next pointers of head to NULL, or setting them to
> LIST_POISON1 and LIST_POISON2 as these two seem to be the ideal
> candidate as they are made to notify(tracked easliy) in case of
> illegal access of list pointers.
>
> Robert your thoughts/comments ??
Following the footsteps of list_del() and list_del_init(), i think we
should have
static inline void list_splice(struct list_head *list, struct list_head *head)
{
if (!list_empty(list)){
__list_splice(list, head);
list->next = LIST_POISON1;
list->prev = LIST_POISON2;
}
}
as the default behaviour of list_splice()
>
>
> >
> >
> > rday
> > --
> >
> > ========================================================================
> > Robert P. J. Day
> > Linux Consulting, Training and Annoying Kernel Pedantry:
> > Have classroom, will lecture.
> >
> > http://crashcourse.ca Waterloo, Ontario, CANADA
> > ========================================================================
> >
>
>
>
>
>
> --
> Thanks & Regards,
> ********************************************
> Manish Katiyar ( http://mkatiyar.googlepages.com )
> 3rd Floor, Fair Winds Block
> EGL Software Park
> Off Intermediate Ring Road
> Bangalore 560071, India
> ***********************************************
>
--
Thanks & Regards,
********************************************
Manish Katiyar ( http://mkatiyar.googlepages.com )
3rd Floor, Fair Winds Block
EGL Software Park
Off Intermediate Ring Road
Bangalore 560071, India
***********************************************
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