On Fri, 14 Apr 2006, Andrew Morton wrote:
> > @@ -305,6 +306,12 @@ struct page * lookup_swap_cache(swp_entr
> > {
> > struct page *page;
> >
> > + if (is_migration_entry(entry)) {
> > + page = migration_entry_to_page(entry);
> > + get_page(page);
> > + return page;
> > + }
>
> What locking ensures that the state of `entry' remains unaltered across the
> is_migration_entry() and migration_entry_to_page() calls?
entry is a variable passed by value to the function.
> > +/*
> > + * Must use a macro for lookup_swap_cache since the functions
> > + * used are only available in certain contexts.
> > + */
> > +#define lookup_swap_cache(__swp) \
> > +({ struct page *p = NULL; \
> > + if (is_migration_entry(__swp)) { \
> > + p = migration_entry_to_page(__swp); \
> > + get_page(p); \
> > + } \
> > + p; \
> > +})
>
> hm. Can nommu do any of this?
If page migration is off (methinks nommu may not support numa) then
the fallback functions are used.
Fallback is
is_migration_entry() == 0
therefore
#define lookup_swap_cache(__swp) NULL
like before.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
