[LTP] [PATCH v2 3/3] syscalls/madvise11: new test for madvise(MADV_DONTNEED)

[zhaogongyi]

Hi,

> 
> Hi!
> > +static void run(void)
> > +{
> > +	char cmd[BUF_SIZE];
> > +	char line[BUF_SIZE];
> > +	char vm_area_addr[128];
> > +
> > +	TEST(madvise(addr, MAP_SIZE, MADV_DONTNEED));
> > +	if (TST_RET == -1) {
> > +		tst_brk(TBROK | TTERRNO, "madvise(%p, %d, 0x%x)",
> > +			addr, MAP_SIZE, MADV_DONTNEED);
> > +	}
> > +
> > +	sprintf(vm_area_addr, "%p", addr);
> > +	sprintf(cmd,
> > +		"cat /proc/%d/smaps | grep %s -A 4 | grep Rss: | grep '0 kB'",
> > +		getpid(), &(vm_area_addr[2]));
> 
> This is way too ugly and may break easily too.
> 
> If we are going to parse the file we should do it properly in C instead.
> Why can't we just read the file line by line until we find the right address
> at the start of the line and once we do look for the Rss?


I have do it with C at first, but it seems not intuitive. I will change back on next version of the patch.

Regards,
Gongyi