On Thu, Jul 29, 2021 at 03:21:28PM +0200, Vlastimil Babka wrote:
> For PREEMPT_RT we will need to disable irqs for this bit spinlock. As a
> preparation, add a flags parameter, and an internal version that takes
> additional bool parameter to control irq saving/restoring (the flags
> parameter is compile-time unused if the bool is a constant false).
>
> Convert ___cmpxchg_double_slab(), which also comes with the same bool
> parameter, to use the internal version.
>
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
On arm64 allmodconfig, the following build warning was new
In file included from ./include/linux/spinlock.h:54,
from ./include/linux/mmzone.h:8,
from ./include/linux/gfp.h:6,
from ./include/linux/mm.h:10,
from mm/slub.c:13:
mm/slub.c: In function '___cmpxchg_double_slab.isra.0':
./include/linux/irqflags.h:177:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
177 | arch_local_irq_restore(flags); \
| ^~~~~~~~~~~~~~~~~~~~~~
mm/slub.c:408:17: note: 'flags' was declared here
408 | unsigned long flags;
| ^~~~~
In file included from ./include/linux/string.h:262,
from ./include/linux/bitmap.h:10,
from ./include/linux/cpumask.h:12,
No idea what's special about arm allmodconfig that confuses the
compiler.
--
Mel Gorman
SUSE Labs
