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The random test:
1. Obtains an address index into the Linear Congruential Generator (LCG)
structure that is dependent on the specified length. The test obtains the data
index as a function of the entered random data seed and the maximum 32 bit
data pattern.
2. Calls the random number generator, using the address index and an initial
address seed of 0, to obtain a random address.
3. Calls the random number generator again, using the data index and initial
user entered data seed, (-rs option), or default of 0, to get the longword of
data to use in testing.
4. Determines whether to perform longword or quadword transactions by using
the lower bit of the random data returned. (Using the lower bit merely saves
another call to the random function to help speed up the test.)
5. Stores the data at the random address, and performs memory barrier to flush
the data out to the Bcache.
6. Reads the data back into the random address.
7. Compares the data written and the data read. In the case of quadword write
and read operations, the longword of random data is shifted left by 32 and
ORd with the original data's compliment to form the quadword.
Memtest test 4 - Victim Eject Test You must first set up a block of data to be
used in the test. The address of this block of data is be read as an input to the
test using the -ba option. (The default is a block of data containing 4 longwords
of 0xFs, then 4 longwords of 0s, then 4 longwords of 0xFs, and finally 4 longwords
of 0s.)
This test:
1. Writes the block of data to the specified starting address.
2. Adds 4 MB to the starting address.
3. Writes arbitrary data. This causes the original data to be ''victimized'' to
memory.
4. Reads the original starting address and verifies that it is correct.
5. Increments the starting address by a block.
6. Repeats the write/write/read procedure for the specified length of memory.
If the memtest command is used to test large sections of memory, it might take
a while for testing to complete.
memtest
Console Commands 13–67
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Troubleshooting
