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authorArnd Bergmann <arnd@arndb.de>2016-08-02 21:04:16 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-02 23:35:08 (GMT)
commita9bfd3321713ecec86282dd2bec04212189f91f1 (patch)
tree1c5981e2d274c3d3fb3b340724939fffb7747eb8
parentf003a1f182bb821f13775338a4bf8711830f927a (diff)
downloadlinux-a9bfd3321713ecec86282dd2bec04212189f91f1.tar.xz
crc32: use ktime_get_ns() for measurement
The crc32 test function measures the elapsed time in nanoseconds, but uses 'struct timespec' for that. We want to remove timespec from the kernel for y2038 compatibility, and ktime_get_ns() also helps make the code simpler here. It is also slightly better to use monontonic time, as we are only interested in the time difference. Link: http://lkml.kernel.org/r/20160617143932.3289626-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: "David S . Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--lib/crc32.c16
1 files changed, 4 insertions, 12 deletions
diff --git a/lib/crc32.c b/lib/crc32.c
index 9a907d4..7fbd1a1 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -979,7 +979,6 @@ static int __init crc32c_test(void)
int i;
int errors = 0;
int bytes = 0;
- struct timespec start, stop;
u64 nsec;
unsigned long flags;
@@ -999,20 +998,17 @@ static int __init crc32c_test(void)
local_irq_save(flags);
local_irq_disable();
- getnstimeofday(&start);
+ nsec = ktime_get_ns();
for (i = 0; i < 100; i++) {
if (test[i].crc32c_le != __crc32c_le(test[i].crc, test_buf +
test[i].start, test[i].length))
errors++;
}
- getnstimeofday(&stop);
+ nsec = ktime_get_ns() - nsec;
local_irq_restore(flags);
local_irq_enable();
- nsec = stop.tv_nsec - start.tv_nsec +
- 1000000000 * (stop.tv_sec - start.tv_sec);
-
pr_info("crc32c: CRC_LE_BITS = %d\n", CRC_LE_BITS);
if (errors)
@@ -1065,7 +1061,6 @@ static int __init crc32_test(void)
int i;
int errors = 0;
int bytes = 0;
- struct timespec start, stop;
u64 nsec;
unsigned long flags;
@@ -1088,7 +1083,7 @@ static int __init crc32_test(void)
local_irq_save(flags);
local_irq_disable();
- getnstimeofday(&start);
+ nsec = ktime_get_ns();
for (i = 0; i < 100; i++) {
if (test[i].crc_le != crc32_le(test[i].crc, test_buf +
test[i].start, test[i].length))
@@ -1098,14 +1093,11 @@ static int __init crc32_test(void)
test[i].start, test[i].length))
errors++;
}
- getnstimeofday(&stop);
+ nsec = ktime_get_ns() - nsec;
local_irq_restore(flags);
local_irq_enable();
- nsec = stop.tv_nsec - start.tv_nsec +
- 1000000000 * (stop.tv_sec - start.tv_sec);
-
pr_info("crc32: CRC_LE_BITS = %d, CRC_BE BITS = %d\n",
CRC_LE_BITS, CRC_BE_BITS);