Re: [PATCH for vm-scalability] usemem: Add new option -Z|--read-again

[Fengguang Wu]

Applied, thanks Teawater!

On Sat, Sep 14, 2019 at 11:07:18AM +0800, Hui Zhu wrote:
> usemem will read memory again after access the memory with this option.
> It can help test the speed that load page from swap to memory.
>
> Signed-off-by: Hui Zhu <teawaterz@xxxxxxxxxxxxxxxxx>
> ---
> usemem.c | 46 ++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/usemem.c b/usemem.c
> index 264d52a..2d31946 100644
> --- a/usemem.c
> +++ b/usemem.c
> @@ -94,6 +94,7 @@ int opt_sync_rw = 0;
> int opt_sync_free = 0;
> int opt_bind_interval = 0;
> unsigned long opt_delay = 0;
> +int opt_read_again = 0;
> int nr_task;
> int nr_thread;
> int nr_cpu;
> @@ -151,6 +152,7 @@ void usage(int ok)
> 	"    -e|--delay          delay for each page in ns\n"
> 	"    -O|--anonymous      mmap with MAP_ANONYMOUS\n"
> 	"    -U|--hugetlb        allocate hugetlbfs page\n"
> +	"    -Z|--read-again     read memory again after access the memory\n"
> 	"    -h|--help           show this message\n"
> 	,		ourname);
>
> @@ -188,6 +190,7 @@ static const struct option opts[] = {
> 	{ "sync-rw"	, 0, NULL, 'y' },
> 	{ "delay"	, 1, NULL, 'e' },
> 	{ "hugetlb"	, 0, NULL, 'U' },
> +	{ "read-again"	, 0, NULL, 'Z' },
> 	{ "help"	, 0, NULL, 'h' },
> 	{ NULL		, 0, NULL, 0 }
> };
> @@ -616,7 +619,7 @@ unsigned long do_unit(unsigned long bytes, struct drand48_data *rand_data,
> 	return rw_bytes;
> }
>
> -static void output_statistics(unsigned long unit_bytes)
> +static void output_statistics(unsigned long unit_bytes, const char *intro)
> {
> 	struct timeval stop;
> 	char buf[1024];
> @@ -629,8 +632,8 @@ static void output_statistics(unsigned long unit_bytes)
> 		(stop.tv_usec - start_time.tv_usec);
> 	throughput = ((unit_bytes * 1000000ULL) >> 10) / delta_us;
> 	len = snprintf(buf, sizeof(buf),
> -			"%lu bytes / %lu usecs = %lu KB/s\n",
> -			unit_bytes, delta_us, throughput);
> +			"%s%lu bytes / %lu usecs = %lu KB/s\n",
> +			intro, unit_bytes, delta_us, throughput);
> 	fflush(stdout);
> 	write(1, buf, len);
> }
> @@ -690,7 +693,34 @@ long do_units(void)
> 	} while (bytes);
>
> 	if (!opt_write_signal_read && unit_bytes)
> -		output_statistics(unit_bytes);
> +		output_statistics(unit_bytes, "");
> +
> +	if (opt_read_again && unit_bytes) {
> +		unsigned long rw_bytes = 0;
> +
> +		gettimeofday(&start_time, NULL);
> +		for (i = 0; i < nptr; i++) {
> +			int rep;
> +
> +			for (rep = 0; rep < reps; rep++) {
> +				if (rep > 0 && !quiet) {
> +					printf(".");
> +					fflush(stdout);
> +				}
> +
> +				rw_bytes += do_rw_once(ptrs[i], lens[i], &rand_data, 1, &rep, reps);
> +
> +				if (msync_mode) {
> +					if ((msync(ptrs[i], lens[i], msync_mode)) == -1) {
> +						fprintf(stderr, "msync failed with error %s \n", strerror(errno));
> +						exit(1);
> +					}
> +				}
> +			}
> +		}
> +
> +		output_statistics(rw_bytes, "read again ");
> +	}
>
> 	if (opt_write_signal_read) {
> 		struct sigaction act;
> @@ -731,7 +761,7 @@ long do_units(void)
> 		sigsuspend(&set);
> 		gettimeofday(&start_time, NULL);
> 		unit_bytes = do_rw_once(buffer, opt_bytes, &rand_data, 1, NULL, 0);
> -		output_statistics(unit_bytes);
> +		output_statistics(unit_bytes, "");
> 	}
>
> 	if (opt_sync_free)
> @@ -879,7 +909,7 @@ int main(int argc, char *argv[])
> 	pagesize = getpagesize();
>
> 	while ((c = getopt_long(argc, argv,
> -				"aAB:f:FPp:gqowRMm:n:t:b:ds:T:Sr:u:j:e:EHDNLWyxOUh", opts, NULL)) != -1)
> +				"aAB:f:FPp:gqowRMm:n:t:b:ds:T:Sr:u:j:e:EHDNLWyxOUZh", opts, NULL)) != -1)
> 		{
> 		switch (c) {
> 		case 'a':
> @@ -1005,6 +1035,10 @@ int main(int argc, char *argv[])
> 			map_hugetlb = MAP_HUGETLB | MAP_HUGE_2MB;
> 			break;
>
> +		case 'Z':
> +			opt_read_again = 1;
> +			break;
> +
> 		default:
> 			usage(1);
> 		}
> --
> 2.7.4