mm: add pmd_t initializer __pmd() to work around a GCC bug.

THP migration is added but only supports x86_64 at the moment. For all
other architectures, swp_entry_to_pmd() only returns a zero pmd_t.

Due to a GCC zero initializer bug #53119, the standard (pmd_t){0}
initializer is not accepted by all GCC versions. __pmd() is a feasible
workaround. In addition, sparc32's pmd_t is an array instead of a single
value, so we need (pmd_t){ {0}, } instead of (pmd_t){0}. Thus,
a different __pmd() definition is needed in sparc32.

Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Zi Yan 2017-08-03 09:17:21 -04:00 committed by David S. Miller
parent 26273939ac
commit 9157259d16

View File

@ -68,6 +68,7 @@ typedef struct { unsigned long iopgprot; } iopgprot_t;
#define iopgprot_val(x) ((x).iopgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { { (x) }, })
#define __iopte(x) ((iopte_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __ctxd(x) ((ctxd_t) { (x) } )
@ -95,6 +96,7 @@ typedef unsigned long iopgprot_t;
#define iopgprot_val(x) (x)
#define __pte(x) (x)
#define __pmd(x) ((pmd_t) { { (x) }, })
#define __iopte(x) (x)
#define __pgd(x) (x)
#define __ctxd(x) (x)