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do_mmap: don't pre-populate the whole file when asked for smaller segment

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The linker maps parts of libs with different access flags,
so we cannot prepopulate the whole file.

[dominique.martinet@cea.fr: moved min and friends in compiler.h]
Change-Id: Ifbeddc0908699099cfae5ce9cc2adc578221db31
This commit is contained in:
Masamichi Takagi
2019-02-07 10:42:27 +09:00
committed by Dominique Martinet
parent 641d9f1b39
commit e828398c8b
3 changed files with 37 additions and 38 deletions
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36
kernel/include/lwk/compiler.h
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@ -545,4 +545,40 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
#define WRITE_ONCE(x, val) \
({ typeof(x) __val = (val); __write_once_size(&(x), &__val, sizeof(__val)); __val; })
#define min(x, y) ({ \
__typeof__(x) _min1 = (x); \
__typeof__(y) _min2 = (y); \
(void) (&_min1 == &_min2); \
_min1 < _min2 ? _min1 : _min2; })
#define max(x, y) ({ \
__typeof__(x) _max1 = (x); \
__typeof__(y) _max2 = (y); \
(void) (&_max1 == &_max2); \
_max1 > _max2 ? _max1 : _max2; })
#define MAX_ERRNO 4095
#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
static inline void *ERR_PTR(long error)
{
return (void *)error;
}
static inline long PTR_ERR(const void *ptr)
{
return (long)ptr;
}
static inline long IS_ERR(const void *ptr)
{
return IS_ERR_VALUE((unsigned long)ptr);
}
static inline long IS_ERR_OR_NULL(const void *ptr)
{
return !ptr || IS_ERR_VALUE((unsigned long)ptr);
}
#endif /* __LWK_COMPILER_H */

36
kernel/include/xpmem_private.h
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@ -48,42 +48,6 @@
#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
#define min(x, y) ({ \
__typeof__(x) _min1 = (x); \
__typeof__(y) _min2 = (y); \
(void) (&_min1 == &_min2); \
_min1 < _min2 ? _min1 : _min2;})
#define max(x, y) ({ \
__typeof__(x) _max1 = (x); \
__typeof__(y) _max2 = (y); \
(void) (&_max1 == &_max2); \
_max1 > _max2 ? _max1 : _max2;})
#define MAX_ERRNO 4095
#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
static inline void * ERR_PTR(long error)
{
return (void *)error;
}
static inline long PTR_ERR(const void *ptr)
{
return (long)ptr;
}
static inline long IS_ERR(const void *ptr)
{
return IS_ERR_VALUE((unsigned long)ptr);
}
static inline long IS_ERR_OR_NULL(const void *ptr)
{
return !ptr || IS_ERR_VALUE((unsigned long)ptr);
}
/*
* Both the xpmem_segid_t and xpmem_apid_t are of type __s64 and designed
* to be opaque to the user. Both consist of the same underlying fields.

3
kernel/syscall.c
View File

@ -1925,13 +1925,12 @@ do_mmap(const uintptr_t addr0, const size_t len0, const int prot,
}
/* Determine pre-populated size */
populate_len = len;
populate_len = memobj ? min(len, memobj->size) : len;
if (!(flags & MAP_ANONYMOUS)) {
if (atomic_cmpxchg4(&memobj->status, MEMOBJ_TO_BE_PREFETCHED,
MEMOBJ_READY)) {
populated_mapping = 1;
populate_len = memobj->size;
}
/* Update PTEs for pre-mapped memory object */