Re: [LTP] [PATCH v4 2/1] add vm tunable file read/write/check func

[Cyril H. <ch...@su...>]

Hi!
> diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
> index f3983d4..64751fd 100644
> --- a/testcases/kernel/mem/lib/mem.c
> +++ b/testcases/kernel/mem/lib/mem.c
> @@ -77,7 +77,7 @@ void write_memcg(void)
>  	snprintf(buf, BUFSIZ, "%d", getpid());
>  	if (write(fd, buf, strlen(buf)) != strlen(buf))
>  		tst_brkm(TBROK|TERRNO, cleanup, "write %s", buf);
> -	close(fd);	
> +	close(fd);
>  }
>  
>  void write_cpusets(void)
> @@ -712,3 +712,82 @@ void check_ksm_options(int *size, int *num, int *unit)
>  				"process number cannot be less 3.");
>  	}
>  }
> +
> +void set_sys_tune(char *sys_file, long long tune)
> +{
> +	int fd;
> +	char buf[BUFSIZ];
> +
> +	tst_resm(TINFO, "set %s to %lld", sys_file, tune);
> +
> +	fd = open(sys_file, O_WRONLY);
> +	if (fd == -1)
> +		tst_brkm(TBROK|TERRNO, cleanup, "open %s", sys_file);
> +	if (snprintf(buf, BUFSIZ, "%lld", tune) < 0)
> +		tst_brkm(TBROK|TERRNO, cleanup, "snprintf");
> +	if (write(fd, buf, strlen(buf)) == -1)
> +		tst_brkm(TBROK|TERRNO, cleanup, "write");

Please add the filename into the message that gets printed when write
has failed too. And possibly enclose the %s with ' eg. 
tst_brkm(... "open '%s'", sys_file).

> +	close(fd);
> +}
> +
> +long long get_sys_tune(char *sys_file)
> +{
> +	int fd;
> +	long long tune;
> +	char buf[BUFSIZ], *endptr;
> +
> +	fd = open(sys_file, O_RDONLY);
> +	if (fd == -1)
> +		tst_brkm(TBROK|TERRNO, cleanup, "open %s", sys_file);
> +	if (read(fd, buf, BUFSIZ) < 0)
> +		tst_brkm(TBROK|TERRNO, cleanup, "read");

And here into the read branch too.

> +	close(fd);
> +
> +	tune = strtoll(buf, &endptr, 10);
> +	if (tune == LLONG_MAX || tune == LLONG_MIN)
> +		tst_brkm(TBROK|TERRNO, cleanup, "strtoll");
> +	if (endptr == buf || (*endptr != '\0' && *endptr != '\n'))
> +		tst_brkm(TBROK, cleanup, "Invalid tunable: %s", buf);
> +
> +	return tune;
> +}
> +
> +/*
> + * the function is designed to make sure the value we get from
> + * sys_file is equal to what we set last.
> + */
> +void check_sys_tune(char *sys_file, long long tune)
> +{
> +	long long val;
> +
> +	val = get_sys_tune(sys_file);
> +	if (val == tune)
> +		tst_resm(TINFO, "confirmed %s = %lld", sys_file, tune);
> +	else
> +		tst_brkm(TBROK, cleanup, "%s = %lld, is not %lld",
> +				sys_file, val, tune);
> +}
> +
> +long long read_meminfo(char *item)
> +{
> +	FILE *fp;
> +	char line[BUFSIZ], buf[BUFSIZ];
> +	long long val;
> +
> +	fp = fopen(PATH_MEMINFO, "r");
> +	if (fp == NULL)
> +		tst_brkm(TBROK|TERRNO, cleanup, "fopen %s", PATH_MEMINFO);
> +	while (fgets(line, BUFSIZ, fp) != NULL) {
> +		if (sscanf(line, "%s %lld ", buf, &val) == 2)
> +			if (strcmp(buf, item) == 0) {
> +				fclose(fp);
> +				return val;
> +			}
> +		continue;
> +	}
> +	fclose(fp);
> +
> +	tst_brkm(TBROK, cleanup, "cannot find \"%s\" in %s",
> +			item, PATH_MEMINFO);
> +}


-- 
Cyril Hrubis
ch...@su...