[dm-devel] [PATCH] multipath-tools: beautify path_latency.c code
Yang Feng
philip.yang at huawei.com
Sat Jun 24 08:39:28 UTC 2017
Hi Xose,
Thanks for your work.
ACK
-Yang
On 2017/6/23 0:46, Xose Vazquez Perez wrote:
> Mainly running scripts/Lindent, from kernel dir, to replace indent spaces
> by tabs.
>
> Cc: Yang Feng <philip.yang at huawei.com>
> Cc: Christophe Varoqui <christophe.varoqui at opensvc.com>
> Cc: device-mapper development <dm-devel at redhat.com>
> Signed-off-by: Xose Vazquez Perez <xose.vazquez at gmail.com>
> ---
> libmultipath/prioritizers/path_latency.c | 354 +++++++++++++++----------------
> 1 file changed, 177 insertions(+), 177 deletions(-)
>
> diff --git a/libmultipath/prioritizers/path_latency.c b/libmultipath/prioritizers/path_latency.c
> index 34b734b..9fc2dfc 100644
> --- a/libmultipath/prioritizers/path_latency.c
> +++ b/libmultipath/prioritizers/path_latency.c
> @@ -17,8 +17,8 @@
> * Author(s): Yang Feng <philip.yang at huawei.com>
> *
> * This file is released under the GPL version 2, or any later version.
> - *
> */
> +
> #include <stdio.h>
> #include <math.h>
> #include <ctype.h>
> @@ -31,27 +31,28 @@
>
> #define pp_pl_log(prio, fmt, args...) condlog(prio, "path_latency prio: " fmt, ##args)
>
> -#define MAX_IO_NUM 200
> -#define MIN_IO_NUM 2
> +#define MAX_IO_NUM 200
> +#define MIN_IO_NUM 2
>
> -#define MAX_BASE_NUM 10
> -#define MIN_BASE_NUM 2
> +#define MAX_BASE_NUM 10
> +#define MIN_BASE_NUM 2
>
> -#define MAX_AVG_LATENCY 100000000. /*Unit: us*/
> -#define MIN_AVG_LATENCY 1. /*Unit: us*/
> +#define MAX_AVG_LATENCY 100000000. /* Unit: us */
> +#define MIN_AVG_LATENCY 1. /* Unit: us */
>
> -#define DEFAULT_PRIORITY 0
> +#define DEFAULT_PRIORITY 0
>
> -#define MAX_CHAR_SIZE 30
> +#define MAX_CHAR_SIZE 30
>
> -#define USEC_PER_SEC 1000000LL
> -#define NSEC_PER_USEC 1000LL
> +#define USEC_PER_SEC 1000000LL
> +#define NSEC_PER_USEC 1000LL
>
> static long long path_latency[MAX_IO_NUM];
>
> static inline long long timeval_to_us(const struct timespec *tv)
> {
> - return ((long long) tv->tv_sec * USEC_PER_SEC) + (tv->tv_nsec / NSEC_PER_USEC);
> + return ((long long)tv->tv_sec * USEC_PER_SEC) +
> + (tv->tv_nsec / NSEC_PER_USEC);
> }
>
> static int do_readsector0(int fd, unsigned int timeout)
> @@ -60,198 +61,197 @@ static int do_readsector0(int fd, unsigned int timeout)
> unsigned char sbuf[SENSE_BUFF_LEN];
> int ret;
>
> - ret = sg_read(fd, &buf[0], 4096, &sbuf[0],
> - SENSE_BUFF_LEN, timeout);
> + ret = sg_read(fd, &buf[0], 4096, &sbuf[0], SENSE_BUFF_LEN, timeout);
>
> return ret;
> }
>
> int check_args_valid(int io_num, int base_num)
> {
> - if ((io_num < MIN_IO_NUM) || (io_num > MAX_IO_NUM))
> - {
> - pp_pl_log(0, "args io_num is outside the valid range");
> - return 0;
> - }
> -
> - if ((base_num < MIN_BASE_NUM) || (base_num > MAX_BASE_NUM))
> - {
> - pp_pl_log(0, "args base_num is outside the valid range");
> - return 0;
> - }
> -
> - return 1;
> + if ((io_num < MIN_IO_NUM) || (io_num > MAX_IO_NUM)) {
> + pp_pl_log(0, "args io_num is outside the valid range");
> + return 0;
> + }
> +
> + if ((base_num < MIN_BASE_NUM) || (base_num > MAX_BASE_NUM)) {
> + pp_pl_log(0, "args base_num is outside the valid range");
> + return 0;
> + }
> +
> + return 1;
> }
>
> -/* In multipath.conf, args form: io_num|base_num. For example,
> -* args is "20|10", this function can get io_num value 20, and
> - base_num value 10.
> -*/
> -static int get_ionum_and_basenum(char *args,
> - int *ionum,
> - int *basenum)
> +/*
> + * In multipath.conf, args form: io_num|base_num. For example,
> + * args is "20|10", this function can get io_num value 20, and
> + * base_num value 10.
> + */
> +static int get_ionum_and_basenum(char *args, int *ionum, int *basenum)
> {
> - char source[MAX_CHAR_SIZE];
> - char vertica = '|';
> - char *endstrbefore = NULL;
> - char *endstrafter = NULL;
> - unsigned int size = strlen(args);
> -
> - if ((args == NULL) || (ionum == NULL) || (basenum == NULL))
> - {
> - pp_pl_log(0, "args string is NULL");
> - return 0;
> - }
> -
> - if ((size < 1) || (size > MAX_CHAR_SIZE-1))
> - {
> - pp_pl_log(0, "args string's size is too long");
> - return 0;
> - }
> -
> - memcpy(source, args, size+1);
> -
> - if (!isdigit(source[0]))
> - {
> - pp_pl_log(0, "invalid prio_args format: %s", source);
> - return 0;
> - }
> -
> - *ionum = (int)strtoul(source, &endstrbefore, 10);
> - if (endstrbefore[0] != vertica)
> - {
> - pp_pl_log(0, "invalid prio_args format: %s", source);
> - return 0;
> - }
> -
> - if (!isdigit(endstrbefore[1]))
> - {
> - pp_pl_log(0, "invalid prio_args format: %s", source);
> - return 0;
> - }
> -
> - *basenum = (long long)strtol(&endstrbefore[1], &endstrafter, 10);
> - if (check_args_valid(*ionum, *basenum) == 0)
> - {
> - return 0;
> - }
> -
> - return 1;
> + char source[MAX_CHAR_SIZE];
> + char vertica = '|';
> + char *endstrbefore = NULL;
> + char *endstrafter = NULL;
> + unsigned int size = strlen(args);
> +
> + if ((args == NULL) || (ionum == NULL) || (basenum == NULL)) {
> + pp_pl_log(0, "args string is NULL");
> + return 0;
> + }
> +
> + if ((size < 1) || (size > MAX_CHAR_SIZE - 1)) {
> + pp_pl_log(0, "args string's size is too long");
> + return 0;
> + }
> +
> + memcpy(source, args, size + 1);
> +
> + if (!isdigit(source[0])) {
> + pp_pl_log(0, "invalid prio_args format: %s", source);
> + return 0;
> + }
> +
> + *ionum = (int)strtoul(source, &endstrbefore, 10);
> + if (endstrbefore[0] != vertica) {
> + pp_pl_log(0, "invalid prio_args format: %s", source);
> + return 0;
> + }
> +
> + if (!isdigit(endstrbefore[1])) {
> + pp_pl_log(0, "invalid prio_args format: %s", source);
> + return 0;
> + }
> +
> + *basenum = (long long)strtol(&endstrbefore[1], &endstrafter, 10);
> + if (check_args_valid(*ionum, *basenum) == 0) {
> + return 0;
> + }
> +
> + return 1;
> }
>
> -long long calc_standard_deviation(long long *path_latency, int size, long long avglatency)
> +long long calc_standard_deviation(long long *path_latency, int size,
> + long long avglatency)
> {
> - int index;
> - long long total = 0;
> + int index;
> + long long total = 0;
>
> - for (index = 0; index < size; index++)
> - {
> - total += (path_latency[index] - avglatency) * (path_latency[index] - avglatency);
> - }
> + for (index = 0; index < size; index++) {
> + total +=
> + (path_latency[index] - avglatency) * (path_latency[index] -
> + avglatency);
> + }
>
> - total /= (size-1);
> + total /= (size - 1);
>
> - return (long long)sqrt((double)total);
> + return (long long)sqrt((double)total);
> }
>
> -int calcPrio(double avglatency, double max_avglatency, double min_avglatency, double base_num)
> +int calcPrio(double avglatency, double max_avglatency, double min_avglatency,
> + double base_num)
> {
> - double lavglatency = log(avglatency)/log(base_num);
> - double lmax_avglatency = log(max_avglatency)/log(base_num);
> - double lmin_avglatency = log(min_avglatency)/log(base_num);
> + double lavglatency = log(avglatency) / log(base_num);
> + double lmax_avglatency = log(max_avglatency) / log(base_num);
> + double lmin_avglatency = log(min_avglatency) / log(base_num);
>
> - if (lavglatency <= lmin_avglatency)
> - return (int)(lmax_avglatency + 1.);
> + if (lavglatency <= lmin_avglatency)
> + return (int)(lmax_avglatency + 1.);
>
> - if (lavglatency > lmax_avglatency)
> - return 0;
> + if (lavglatency > lmax_avglatency)
> + return 0;
>
> - return (int)(lmax_avglatency - lavglatency + 1.);
> + return (int)(lmax_avglatency - lavglatency + 1.);
> }
>
> /* Calc the latency interval corresponding to the average latency */
> long long calc_latency_interval(double avglatency, double max_avglatency,
> - double min_avglatency, double base_num)
> + double min_avglatency, double base_num)
> {
> - double lavglatency = log(avglatency)/log(base_num);
> - double lmax_avglatency = log(max_avglatency)/log(base_num);
> - double lmin_avglatency = log(min_avglatency)/log(base_num);
> -
> - if ((lavglatency <= lmin_avglatency)
> - || (lavglatency > lmax_avglatency))
> - return 0;/* Invalid value */
> -
> - if ((double)((int)lavglatency) == lavglatency)
> - return (long long)(avglatency - (avglatency / base_num));
> - else
> - return (long long)(pow(base_num, (double)((int)lavglatency + 1))
> - - pow(base_num, (double)((int)lavglatency)));
> + double lavglatency = log(avglatency) / log(base_num);
> + double lmax_avglatency = log(max_avglatency) / log(base_num);
> + double lmin_avglatency = log(min_avglatency) / log(base_num);
> +
> + if ((lavglatency <= lmin_avglatency)
> + || (lavglatency > lmax_avglatency))
> + return 0; /* Invalid value */
> +
> + if ((double)((int)lavglatency) == lavglatency)
> + return (long long)(avglatency - (avglatency / base_num));
> + else
> + return (long long)(pow(base_num, (double)((int)lavglatency + 1))
> + - pow(base_num, (double)((int)lavglatency)));
> }
>
> -int getprio (struct path *pp, char *args, unsigned int timeout)
> +int getprio(struct path *pp, char *args, unsigned int timeout)
> {
> - int rc, temp;
> - int index = 0;
> - int io_num;
> - int base_num;
> - long long avglatency;
> - long long latency_interval;
> - long long standard_deviation;
> - long long toldelay = 0;
> - long long before, after;
> - struct timespec tv;
> -
> - if (pp->fd < 0)
> - return -1;
> -
> - if (get_ionum_and_basenum(args, &io_num, &base_num) == 0)
> - {
> - pp_pl_log(0, "%s: get path_latency args fail", pp->dev);
> - return DEFAULT_PRIORITY;
> - }
> -
> - memset(path_latency, 0, sizeof(path_latency));
> -
> - temp = io_num;
> - while (temp-- > 0)
> - {
> - (void)clock_gettime(CLOCK_MONOTONIC, &tv);
> - before = timeval_to_us(&tv);
> -
> - if (do_readsector0(pp->fd, timeout) == 2)
> - {
> - pp_pl_log(0, "%s: path down", pp->dev);
> - return -1;
> - }
> -
> - (void)clock_gettime(CLOCK_MONOTONIC, &tv);
> - after = timeval_to_us(&tv);
> -
> - path_latency[index] = after - before;
> - toldelay += path_latency[index++];
> - }
> -
> - avglatency = toldelay/(long long)io_num;
> - pp_pl_log(4, "%s: average latency is (%lld us)", pp->dev, avglatency);
> -
> - if (avglatency > MAX_AVG_LATENCY)
> - {
> - pp_pl_log(0, "%s: average latency (%lld us) is outside the thresold (%lld us)",
> - pp->dev, avglatency, (long long)MAX_AVG_LATENCY);
> - return DEFAULT_PRIORITY;
> - }
> -
> - /* Min average latency and max average latency are constant, the args base_num
> - set can change latency_interval value corresponding to avglatency and is not constant.
> - Warn the user if latency_interval is smaller than (2 * standard_deviation), or equal */
> - standard_deviation = calc_standard_deviation(path_latency, index, avglatency);
> - latency_interval = calc_latency_interval(avglatency, MAX_AVG_LATENCY, MIN_AVG_LATENCY, base_num);
> - if ((latency_interval!= 0)
> - && (latency_interval <= (2 * standard_deviation)))
> - pp_pl_log(3, "%s: latency interval (%lld) according to average latency (%lld us) is smaller than "
> - "2 * standard deviation (%lld us), or equal, args base_num (%d) needs to be set bigger value",
> - pp->dev, latency_interval, avglatency, standard_deviation, base_num);
> -
> - rc = calcPrio(avglatency, MAX_AVG_LATENCY, MIN_AVG_LATENCY, base_num);
> - return rc;
> + int rc, temp;
> + int index = 0;
> + int io_num;
> + int base_num;
> + long long avglatency;
> + long long latency_interval;
> + long long standard_deviation;
> + long long toldelay = 0;
> + long long before, after;
> + struct timespec tv;
> +
> + if (pp->fd < 0)
> + return -1;
> +
> + if (get_ionum_and_basenum(args, &io_num, &base_num) == 0) {
> + pp_pl_log(0, "%s: get path_latency args fail", pp->dev);
> + return DEFAULT_PRIORITY;
> + }
> +
> + memset(path_latency, 0, sizeof(path_latency));
> +
> + temp = io_num;
> + while (temp-- > 0) {
> + (void)clock_gettime(CLOCK_MONOTONIC, &tv);
> + before = timeval_to_us(&tv);
> +
> + if (do_readsector0(pp->fd, timeout) == 2) {
> + pp_pl_log(0, "%s: path down", pp->dev);
> + return -1;
> + }
> +
> + (void)clock_gettime(CLOCK_MONOTONIC, &tv);
> + after = timeval_to_us(&tv);
> +
> + path_latency[index] = after - before;
> + toldelay += path_latency[index++];
> + }
> +
> + avglatency = toldelay / (long long)io_num;
> + pp_pl_log(4, "%s: average latency is (%lld us)", pp->dev, avglatency);
> +
> + if (avglatency > MAX_AVG_LATENCY) {
> + pp_pl_log(0,
> + "%s: average latency (%lld us) is outside the thresold (%lld us)",
> + pp->dev, avglatency, (long long)MAX_AVG_LATENCY);
> + return DEFAULT_PRIORITY;
> + }
> +
> + /*
> + * Min average latency and max average latency are constant, the args
> + * base_num set can change latency_interval value corresponding to
> + * avglatency and is not constant.
> + * Warn the user if latency_interval is smaller than (2 * standard_deviation),
> + * or equal.
> + */
> + standard_deviation =
> + calc_standard_deviation(path_latency, index, avglatency);
> + latency_interval =
> + calc_latency_interval(avglatency, MAX_AVG_LATENCY, MIN_AVG_LATENCY,
> + base_num);
> + if ((latency_interval != 0)
> + && (latency_interval <= (2 * standard_deviation)))
> + pp_pl_log(3,
> + "%s: latency interval (%lld) according to average latency (%lld us) is smaller than "
> + "2 * standard deviation (%lld us), or equal, args base_num (%d) needs to be set bigger value",
> + pp->dev, latency_interval, avglatency,
> + standard_deviation, base_num);
> +
> + rc = calcPrio(avglatency, MAX_AVG_LATENCY, MIN_AVG_LATENCY, base_num);
> + return rc;
> }
>
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