On Fri, 4 Nov 2005, Andrew Morton wrote:
> Hugh Dickins <[email protected]> wrote:
>
> > While leaving most of the page_private() mods in place for the moment,
> > could we please try this patch, or something like it? Again to overlay
> > the spinlock_t from &page->private onwards, with corrected BUILD_BUG_ON
> > that we don't go beyond ->lru; with poisoning of the fields overlaid,
> > and unsplit config verifying that the split config is safe to use them.
>
> Does your family know you do this sort of thing?
They are beginning to suspect it, so I've made sure they're still asleep.
> What happened to my suggestion that we use anonymous structs here, and
> abandon gcc-2.9x?
Much as I'd hate split ptlock to enlarge struct page, I'd hate it to be
the last straw that forced you off gcc-2.9x: it does not deserve that.
But also, I just misunderstood you until now: I'd been stupidly thinking
you meant an anonymous union in place of your current u there; whereas
you meant extending the union to cover mapping, index, lru. Hmm.
Well, if you're actively seeking a excuse to abandon gcc-2.9x? But
although you're its best-known advocate, I think you're not alone.
Shall we wait for a more pressing reason?
> > -#define page_private(page) ((page)->u.private)
> > -#define set_page_private(page, v) ((page)->u.private = (v))
> > +#define page_private(page) ((page)->private)
> > +#define set_page_private(page, v) ((page)->private = (v))
>
> Need to rename ->private to ->_private here, otherwise people will start
> using page->private again.
I'm happy for people to use page->private again. I thought we
ought to try out this minimal patch first, for reassurance that the
arches are not using those fields of a pagetable struct page; but that
once it's had some exposure, we'd revert the page_private mods elsewhere.
There's no point to that wrapper with the union gone, is there?
Hugh
-
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]