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pager_req_map(): do not take mmap_sem if not needed

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Balazs Gerofi
2018-06-07 07:12:41 +09:00
parent ec375da27a
commit f148863586
1 changed files with 9 additions and 7 deletions
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16
executer/kernel/mcctrl/syscall.c
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@ -1673,20 +1673,22 @@ static int pager_req_map(ihk_os_t os, int fd, size_t len, off_t off,
maxprot |= PROT_EXEC;
}
down_write(&current->mm->mmap_sem);
prot_and_flags = MAP_SHARED |
(prot_and_flags & (MAP_POPULATE | MAP_LOCKED));
#define ANY_WHERE 0
if (prot_and_flags & MAP_LOCKED) prot_and_flags |= MAP_POPULATE;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,5,0)
down_write(&current->mm->mmap_sem);
va = do_mmap_pgoff(file, ANY_WHERE, len, maxprot,
MAP_SHARED | (prot_and_flags & (MAP_POPULATE | MAP_LOCKED)), pgoff);
#endif
prot_and_flags, pgoff);
up_write(&current->mm->mmap_sem);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
va = vm_mmap(file, ANY_WHERE, len, maxprot, MAP_SHARED |
(prot_and_flags & (MAP_POPULATE | MAP_LOCKED)), pgoff << PAGE_SHIFT);
#else
va = vm_mmap(file, ANY_WHERE, len, maxprot,
prot_and_flags, pgoff << PAGE_SHIFT);
#endif
if (IS_ERR_VALUE(va)) {