Re: [PATCH] mmc_test: use ktime_get_ts64 for timestamps

From: Ulf Hansson
Date: Thu Nov 30 2017 - 08:10:09 EST


On 27 November 2017 at 12:53, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> Calling getnstimeofday() can suffer from time jumps and from the
> y2038 overflow, so it is not appropriate here. Using ktime_get_ts64()
> solves both problems. Using ktime_get() with ktime_t timestamps would
> also work, but it seems that we mainly want to print the times as
> seconds+nanoseconds, so it would require an extra division in the output.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks, applied for next!

Kind regards
Uffe

> ---
> drivers/mmc/core/mmc_test.c | 88 ++++++++++++++++++++++-----------------------
> 1 file changed, 42 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc_test.c b/drivers/mmc/core/mmc_test.c
> index 478869805b96..eae8810d22d9 100644
> --- a/drivers/mmc/core/mmc_test.c
> +++ b/drivers/mmc/core/mmc_test.c
> @@ -101,7 +101,7 @@ struct mmc_test_transfer_result {
> struct list_head link;
> unsigned int count;
> unsigned int sectors;
> - struct timespec ts;
> + struct timespec64 ts;
> unsigned int rate;
> unsigned int iops;
> };
> @@ -515,14 +515,11 @@ static int mmc_test_map_sg_max_scatter(struct mmc_test_mem *mem,
> /*
> * Calculate transfer rate in bytes per second.
> */
> -static unsigned int mmc_test_rate(uint64_t bytes, struct timespec *ts)
> +static unsigned int mmc_test_rate(uint64_t bytes, struct timespec64 *ts)
> {
> uint64_t ns;
>
> - ns = ts->tv_sec;
> - ns *= 1000000000;
> - ns += ts->tv_nsec;
> -
> + ns = timespec64_to_ns(ts);
> bytes *= 1000000000;
>
> while (ns > UINT_MAX) {
> @@ -542,7 +539,7 @@ static unsigned int mmc_test_rate(uint64_t bytes, struct timespec *ts)
> * Save transfer results for future usage
> */
> static void mmc_test_save_transfer_result(struct mmc_test_card *test,
> - unsigned int count, unsigned int sectors, struct timespec ts,
> + unsigned int count, unsigned int sectors, struct timespec64 ts,
> unsigned int rate, unsigned int iops)
> {
> struct mmc_test_transfer_result *tr;
> @@ -567,21 +564,21 @@ static void mmc_test_save_transfer_result(struct mmc_test_card *test,
> * Print the transfer rate.
> */
> static void mmc_test_print_rate(struct mmc_test_card *test, uint64_t bytes,
> - struct timespec *ts1, struct timespec *ts2)
> + struct timespec64 *ts1, struct timespec64 *ts2)
> {
> unsigned int rate, iops, sectors = bytes >> 9;
> - struct timespec ts;
> + struct timespec64 ts;
>
> - ts = timespec_sub(*ts2, *ts1);
> + ts = timespec64_sub(*ts2, *ts1);
>
> rate = mmc_test_rate(bytes, &ts);
> iops = mmc_test_rate(100, &ts); /* I/O ops per sec x 100 */
>
> - pr_info("%s: Transfer of %u sectors (%u%s KiB) took %lu.%09lu "
> + pr_info("%s: Transfer of %u sectors (%u%s KiB) took %llu.%09u "
> "seconds (%u kB/s, %u KiB/s, %u.%02u IOPS)\n",
> mmc_hostname(test->card->host), sectors, sectors >> 1,
> - (sectors & 1 ? ".5" : ""), (unsigned long)ts.tv_sec,
> - (unsigned long)ts.tv_nsec, rate / 1000, rate / 1024,
> + (sectors & 1 ? ".5" : ""), (u64)ts.tv_sec,
> + (u32)ts.tv_nsec, rate / 1000, rate / 1024,
> iops / 100, iops % 100);
>
> mmc_test_save_transfer_result(test, 1, sectors, ts, rate, iops);
> @@ -591,24 +588,24 @@ static void mmc_test_print_rate(struct mmc_test_card *test, uint64_t bytes,
> * Print the average transfer rate.
> */
> static void mmc_test_print_avg_rate(struct mmc_test_card *test, uint64_t bytes,
> - unsigned int count, struct timespec *ts1,
> - struct timespec *ts2)
> + unsigned int count, struct timespec64 *ts1,
> + struct timespec64 *ts2)
> {
> unsigned int rate, iops, sectors = bytes >> 9;
> uint64_t tot = bytes * count;
> - struct timespec ts;
> + struct timespec64 ts;
>
> - ts = timespec_sub(*ts2, *ts1);
> + ts = timespec64_sub(*ts2, *ts1);
>
> rate = mmc_test_rate(tot, &ts);
> iops = mmc_test_rate(count * 100, &ts); /* I/O ops per sec x 100 */
>
> pr_info("%s: Transfer of %u x %u sectors (%u x %u%s KiB) took "
> - "%lu.%09lu seconds (%u kB/s, %u KiB/s, "
> + "%llu.%09u seconds (%u kB/s, %u KiB/s, "
> "%u.%02u IOPS, sg_len %d)\n",
> mmc_hostname(test->card->host), count, sectors, count,
> sectors >> 1, (sectors & 1 ? ".5" : ""),
> - (unsigned long)ts.tv_sec, (unsigned long)ts.tv_nsec,
> + (u64)ts.tv_sec, (u32)ts.tv_nsec,
> rate / 1000, rate / 1024, iops / 100, iops % 100,
> test->area.sg_len);
>
> @@ -1449,7 +1446,7 @@ static int mmc_test_area_io_seq(struct mmc_test_card *test, unsigned long sz,
> int max_scatter, int timed, int count,
> bool nonblock, int min_sg_len)
> {
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret = 0;
> int i;
> struct mmc_test_area *t = &test->area;
> @@ -1475,7 +1472,7 @@ static int mmc_test_area_io_seq(struct mmc_test_card *test, unsigned long sz,
> return ret;
>
> if (timed)
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> if (nonblock)
> ret = mmc_test_nonblock_transfer(test, t->sg, t->sg_len,
> dev_addr, t->blocks, 512, write, count);
> @@ -1489,7 +1486,7 @@ static int mmc_test_area_io_seq(struct mmc_test_card *test, unsigned long sz,
> return ret;
>
> if (timed)
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
>
> if (timed)
> mmc_test_print_avg_rate(test, sz, count, &ts1, &ts2);
> @@ -1747,7 +1744,7 @@ static int mmc_test_profile_trim_perf(struct mmc_test_card *test)
> struct mmc_test_area *t = &test->area;
> unsigned long sz;
> unsigned int dev_addr;
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret;
>
> if (!mmc_can_trim(test->card))
> @@ -1758,19 +1755,19 @@ static int mmc_test_profile_trim_perf(struct mmc_test_card *test)
>
> for (sz = 512; sz < t->max_sz; sz <<= 1) {
> dev_addr = t->dev_addr + (sz >> 9);
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> ret = mmc_erase(test->card, dev_addr, sz >> 9, MMC_TRIM_ARG);
> if (ret)
> return ret;
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
> mmc_test_print_rate(test, sz, &ts1, &ts2);
> }
> dev_addr = t->dev_addr;
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> ret = mmc_erase(test->card, dev_addr, sz >> 9, MMC_TRIM_ARG);
> if (ret)
> return ret;
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
> mmc_test_print_rate(test, sz, &ts1, &ts2);
> return 0;
> }
> @@ -1779,19 +1776,19 @@ static int mmc_test_seq_read_perf(struct mmc_test_card *test, unsigned long sz)
> {
> struct mmc_test_area *t = &test->area;
> unsigned int dev_addr, i, cnt;
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret;
>
> cnt = t->max_sz / sz;
> dev_addr = t->dev_addr;
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> for (i = 0; i < cnt; i++) {
> ret = mmc_test_area_io(test, sz, dev_addr, 0, 0, 0);
> if (ret)
> return ret;
> dev_addr += (sz >> 9);
> }
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
> mmc_test_print_avg_rate(test, sz, cnt, &ts1, &ts2);
> return 0;
> }
> @@ -1818,7 +1815,7 @@ static int mmc_test_seq_write_perf(struct mmc_test_card *test, unsigned long sz)
> {
> struct mmc_test_area *t = &test->area;
> unsigned int dev_addr, i, cnt;
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret;
>
> ret = mmc_test_area_erase(test);
> @@ -1826,14 +1823,14 @@ static int mmc_test_seq_write_perf(struct mmc_test_card *test, unsigned long sz)
> return ret;
> cnt = t->max_sz / sz;
> dev_addr = t->dev_addr;
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> for (i = 0; i < cnt; i++) {
> ret = mmc_test_area_io(test, sz, dev_addr, 1, 0, 0);
> if (ret)
> return ret;
> dev_addr += (sz >> 9);
> }
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
> mmc_test_print_avg_rate(test, sz, cnt, &ts1, &ts2);
> return 0;
> }
> @@ -1864,7 +1861,7 @@ static int mmc_test_profile_seq_trim_perf(struct mmc_test_card *test)
> struct mmc_test_area *t = &test->area;
> unsigned long sz;
> unsigned int dev_addr, i, cnt;
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret;
>
> if (!mmc_can_trim(test->card))
> @@ -1882,7 +1879,7 @@ static int mmc_test_profile_seq_trim_perf(struct mmc_test_card *test)
> return ret;
> cnt = t->max_sz / sz;
> dev_addr = t->dev_addr;
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> for (i = 0; i < cnt; i++) {
> ret = mmc_erase(test->card, dev_addr, sz >> 9,
> MMC_TRIM_ARG);
> @@ -1890,7 +1887,7 @@ static int mmc_test_profile_seq_trim_perf(struct mmc_test_card *test)
> return ret;
> dev_addr += (sz >> 9);
> }
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
> mmc_test_print_avg_rate(test, sz, cnt, &ts1, &ts2);
> }
> return 0;
> @@ -1912,7 +1909,7 @@ static int mmc_test_rnd_perf(struct mmc_test_card *test, int write, int print,
> {
> unsigned int dev_addr, cnt, rnd_addr, range1, range2, last_ea = 0, ea;
> unsigned int ssz;
> - struct timespec ts1, ts2, ts;
> + struct timespec64 ts1, ts2, ts;
> int ret;
>
> ssz = sz >> 9;
> @@ -1921,10 +1918,10 @@ static int mmc_test_rnd_perf(struct mmc_test_card *test, int write, int print,
> range1 = rnd_addr / test->card->pref_erase;
> range2 = range1 / ssz;
>
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> for (cnt = 0; cnt < UINT_MAX; cnt++) {
> - getnstimeofday(&ts2);
> - ts = timespec_sub(ts2, ts1);
> + ktime_get_ts64(&ts2);
> + ts = timespec64_sub(ts2, ts1);
> if (ts.tv_sec >= 10)
> break;
> ea = mmc_test_rnd_num(range1);
> @@ -1998,7 +1995,7 @@ static int mmc_test_seq_perf(struct mmc_test_card *test, int write,
> {
> struct mmc_test_area *t = &test->area;
> unsigned int dev_addr, i, cnt, sz, ssz;
> - struct timespec ts1, ts2;
> + struct timespec64 ts1, ts2;
> int ret;
>
> sz = t->max_tfr;
> @@ -2025,7 +2022,7 @@ static int mmc_test_seq_perf(struct mmc_test_card *test, int write,
> cnt = tot_sz / sz;
> dev_addr &= 0xffff0000; /* Round to 64MiB boundary */
>
> - getnstimeofday(&ts1);
> + ktime_get_ts64(&ts1);
> for (i = 0; i < cnt; i++) {
> ret = mmc_test_area_io(test, sz, dev_addr, write,
> max_scatter, 0);
> @@ -2033,7 +2030,7 @@ static int mmc_test_seq_perf(struct mmc_test_card *test, int write,
> return ret;
> dev_addr += ssz;
> }
> - getnstimeofday(&ts2);
> + ktime_get_ts64(&ts2);
>
> mmc_test_print_avg_rate(test, sz, cnt, &ts1, &ts2);
>
> @@ -3066,10 +3063,9 @@ static int mtf_test_show(struct seq_file *sf, void *data)
> seq_printf(sf, "Test %d: %d\n", gr->testcase + 1, gr->result);
>
> list_for_each_entry(tr, &gr->tr_lst, link) {
> - seq_printf(sf, "%u %d %lu.%09lu %u %u.%02u\n",
> + seq_printf(sf, "%u %d %llu.%09u %u %u.%02u\n",
> tr->count, tr->sectors,
> - (unsigned long)tr->ts.tv_sec,
> - (unsigned long)tr->ts.tv_nsec,
> + (u64)tr->ts.tv_sec, (u32)tr->ts.tv_nsec,
> tr->rate, tr->iops / 100, tr->iops % 100);
> }
> }
> --
> 2.9.0
>