dd 根據不同block size 測試eMMC 讀寫速度

因項目需求，寫了一個讀寫eMMC 的腳本來測試eMMC 讀寫速度

寫速度測試腳本：

#!/bin/bash

TEST_FILE_SIZE=134217728

Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M

for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864

do

Calculate number of segments required to copy

COUNT= ( ( (( ((TEST_FILE_SIZE/$BLOCK_SIZE))

if [ $COUNT -le 0 ];

then

echo"Block size of $BLOCK_SIZE estimated to require C O U N T b l o c k s , a b o r t i n g f u r t h e r t e s t s . " b r e a k f i e c h o 3 > / p r o c / s y s / v m / d r o p c a c h e s d d i f = / d e v / z e r o o f = / v a r / t e s t . d b f b s = COUNT blocks, aborting further tests." break fi echo 3>/proc/sys/vm/drop_caches dd if=/dev/zero of=/var/test.dbf bs= COUNTblocks,abortingfurthertests."breakfiecho3>/proc/sys/vm/dropc​achesddif=/dev/zeroof=/var/test.dbfbs=BLOCK_SIZE count=$COUNT;sync

rm /var/test.dbf

sync

done

測試結果：

262144+0 records in

262144+0 records out

134217728 bytes transferred in 7.305 secs (18373405 bytes/sec)

131072+0 records in

131072+0 records out

134217728 bytes transferred in 4.859 secs (27622500 bytes/sec)

65536+0 records in

65536+0 records out

134217728 bytes transferred in 3.894 secs (34467829 bytes/sec)

32768+0 records in

32768+0 records out

134217728 bytes transferred in 3.434 secs (39084952 bytes/sec)

16384+0 records in

16384+0 records out

134217728 bytes transferred in 2.845 secs (47176705 bytes/sec)

8192+0 records in

8192+0 records out

134217728 bytes transferred in 2.851 secs (47077421 bytes/sec)

4096+0 records in

4096+0 records out

134217728 bytes transferred in 2.830 secs (47426759 bytes/sec)

2048+0 records in

2048+0 records out

134217728 bytes transferred in 3.035 secs (44223304 bytes/sec)

1024+0 records in

1024+0 records out

134217728 bytes transferred in 3.277 secs (40957500 bytes/sec)

512+0 records in

512+0 records out

134217728 bytes transferred in 3.023 secs (44398851 bytes/sec)

256+0 records in

256+0 records out

134217728 bytes transferred in 2.680 secs (50081241 bytes/sec)

128+0 records in

128+0 records out

134217728 bytes transferred in 2.869 secs (46782059 bytes/sec)

64+0 records in

64+0 records out

134217728 bytes transferred in 2.981 secs (45024397 bytes/sec)

32+0 records in

32+0 records out

134217728 bytes transferred in 3.095 secs (43365986 bytes/sec)

16+0 records in

16+0 records out

134217728 bytes transferred in 2.985 secs (44964062 bytes/sec)

8+0 records in

8+0 records out

134217728 bytes transferred in 2.915 secs (46043817 bytes/sec)

4+0 records in

4+0 records out

134217728 bytes transferred in 2.914 secs (46059618 bytes/sec)

2+0 records in

2+0 records out

134217728 bytes transferred in 2.957 secs (45389830 bytes/sec)

====================================================================

讀eMMC 腳本：

#!/bin/bash

TEST_FILE_SIZE=134217728

Create test file

echo ‘Generating test file…’

BLOCK_SIZE=65536

COUNT= ( ( (( ((TEST_FILE_SIZE / B L O C K S I Z E ) ) d d i f = / d e v / u r a n d o m o f = / v a r / t e s t . d b f b s = BLOCK_SIZE)) dd if=/dev/urandom of=/var/test.dbf bs= BLOCKS​IZE))ddif=/dev/urandomof=/var/test.dbfbs=BLOCK_SIZE count=$COUNT;sync

Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M

for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864

do

echo 3>/proc/sys/vm/drop_caches

dd if=/var/test.dbf of=/dev/null bs=$BLOCK_SIZE;sync

done

測試結果：

Generating test file…

2048+0 records in

2048+0 records out

134217728 bytes transferred in 6.330 secs (21203432 bytes/sec)

262144+0 records in

262144+0 records out

134217728 bytes transferred in 1.271 secs (105600100 bytes/sec)

131072+0 records in

131072+0 records out

134217728 bytes transferred in 0.776 secs (172960989 bytes/sec)

65536+0 records in

65536+0 records out

134217728 bytes transferred in 0.482 secs (278460016 bytes/sec)

32768+0 records in

32768+0 records out

134217728 bytes transferred in 0.312 secs (430185025 bytes/sec)

16384+0 records in

16384+0 records out

134217728 bytes transferred in 0.236 secs (568719186 bytes/sec)

8192+0 records in

8192+0 records out

134217728 bytes transferred in 0.200 secs (671088640 bytes/sec)

4096+0 records in

4096+0 records out

134217728 bytes transferred in 0.185 secs (725501232 bytes/sec)

2048+0 records in

2048+0 records out

134217728 bytes transferred in 0.178 secs (754032179 bytes/sec)

1024+0 records in

1024+0 records out

134217728 bytes transferred in 0.154 secs (871543688 bytes/sec)

512+0 records in

512+0 records out

134217728 bytes transferred in 0.295 secs (454975349 bytes/sec)

256+0 records in

256+0 records out

134217728 bytes transferred in 0.351 secs (382386689 bytes/sec)

128+0 records in

128+0 records out

134217728 bytes transferred in 0.267 secs (502688119 bytes/sec)

64+0 records in

64+0 records out

134217728 bytes transferred in 0.232 secs (578524689 bytes/sec)

32+0 records in

32+0 records out

134217728 bytes transferred in 0.293 secs (458080982 bytes/sec)

16+0 records in

16+0 records out

134217728 bytes transferred in 0.255 secs (526344031 bytes/sec)

8+0 records in

8+0 records out

134217728 bytes transferred in 0.288 secs (466033777 bytes/sec)

4+0 records in

4+0 records out

134217728 bytes transferred in 0.250 secs (536870912 bytes/sec)

2+0 records in

2+0 records out

134217728 bytes transferred in 0.328 secs (409200390 bytes/sec)

根據上面結果看，不同的block size 讀寫速度不一樣，每個硬體有一個最優的讀寫速度的size