On Wed, 9 Nov 2016 15:01:17 -0800 Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
> On Wed, Nov 09, 2016 at 02:33:04PM -0800, Andrew Morton wrote:
> > On Wed, 9 Nov 2016 11:55:31 +0100 Vitaly Wool <vitalywool@xxxxxxxxx> wrote:
> >
> > > Subject: [PATCH v3] z3fold: use per-page read/write lock
> >
> > I've rewritten the title to "mm/z3fold.c: use per-page spinlock"
> >
> > (I prefer to have "mm" in the title to easily identify it as an MM
> > patch, and using "mm: z3fold: ..." seems odd when the actual pathname
> > conveys the same info.)
>
> Still think it needs to be raw_spinlock_t, otherwise the build bug on
> on the header size will break again.
>
> Better would be to fix that build bug though
Yeah, that triggers for me immediately. We could suppress it with
something silly like
--- a/mm/z3fold.c~z3fold-use-per-page-read-write-lock-fix
+++ a/mm/z3fold.c
@@ -872,7 +872,7 @@ MODULE_ALIAS("zpool-z3fold");
static int __init init_z3fold(void)
{
/* Make sure the z3fold header will fit in one chunk */
- BUILD_BUG_ON(sizeof(struct z3fold_header) > ZHDR_SIZE_ALIGNED);
+ BUILD_BUG_ON(sizeof(struct z3fold_header) - sizeof(spinlock_t) > ZHDR_SIZE_ALIGNED);
zpool_register_driver(&z3fold_zpool_driver);
return 0;
but that doesn't fix anything - the header is just too large with
lockdep enabled.
I'll drop the patch for now.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>