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 <teawat...@linux.alibaba.com>
---
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
