[LTP] [PATCH v2] mem/hugetlb: shift an empty region to use in hugemmap02.c

[Cyril Hrubis]

Hi!
> okay, seems you are right. I tried and achieved another one,  following
> code test pass on my s390x system.
> -----------------------------------------
> int range_is_mapped(unsigned long low, unsigned long high)
> {
>     FILE *f = SAFE_FOPEN(NULL, "/proc/self/maps", "r");

If we start to use SAFE_MACROS() here we have to pass the cleanup
callback to the range_is_mapped() as a first parameter so that we can
pass correct cleanup callback to the SAFE_MACROS().

>     char buf[512];
> 
>     while (!feof(f)) {
>         unsigned long start, end;
>         int ret;
> 
>         ret = fscanf(f, "%lx-%lx %[^\n]%*c]", &start, &end, buf);

You can do even better with:

                ret = fscanf(f, "%lx-%lx %*[^\n]\n", &start, &end);

Which says read two long ints and then ignore everything until the end
of line.

You could have ommited the last '\n' in the format string, but then you
would need to exit the loop when the fscanf() returns -1 since the
feof() would not exit the loop since there would still be the last
newline in the buffer after we read the last line...

-- 
Cyril Hrubis
chrubis@suse.cz