The patch titled
Subject: crc32: use ktime_get_ns() for measurement
has been added to the -mm tree. Its filename is
crc32-use-ktime_get_ns-for-measurement.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/crc32-use-ktime_get_ns-for-measurement.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/crc32-use-ktime_get_ns-for-measurement.patch
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------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: 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@xxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: "David S . Miller" <davem@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/crc32.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff -puN lib/crc32.c~crc32-use-ktime_get_ns-for-measurement lib/crc32.c
--- a/lib/crc32.c~crc32-use-ktime_get_ns-for-measurement
+++ a/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);
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
procfs-avoid-32-bit-time_t-in-proc-stat.patch
crc32-use-ktime_get_ns-for-measurement.patch
nilfs2-replace-nilfs_warning-with-nilfs_msg-fix.patch
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