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Comparison of Cache Replacement Policies using GEM5 Simulator Teammates – Bhagyashree Nivin Sri Divya
Comparison of Cache Replacement Policies using GEM5 Simulator
Teammates – Bhagyashree Nivin Sri Divya
Research Ideas
1. Increase the cache levels
2. Cache Replacement Favors a specific locality
3. Mixing of Cache Replacement algorithm in different levels
4. Cache associativity
Gem5 Simulator
Install : hg clone http://repo.gem5.org/gem5-stable Build: build gem5 with “scons” e.g scons build/X86/gem5.opt
We are using matrix multiplication program for performance Evaluation.
Cache Replacement Favors a specific locality
9060000
9080000
9100000
9120000
9140000
9160000
9180000
9200000
9220000
1 2 3 4 5
FIFO LRU RANDOM
for ( int i=0; i<n;i++) for(int j=0; j<n; j++) data += a[j][i];
Level 2 Cache Hierarchy
Set Associativity
0
0.2
0.4
0.6
0.8
1
1.2
L1(random)
L2(random)
L3(random)
L1 (lru) L2 (lru) L3 (lru)
2 way
4 way
8 way
248
842
Inclusive & Exclusive Caches
Three Level Cache - System Architecture
Configuration – Different Cache Policy on Different
Levels • Configuration
– 1Ghz clock machine
– Coherent crossbar
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Matrix Size 32
L1_D
L1_I
L2
L3
fifo 32 0.017048 0.001168 0.723251 0.913687
fifo_lru 32 0.017067 0.001168 0.70857 0.925618
fifo_lru 32 0.017072 0.001168 0.738064 0.886211
lru 32 0.016284 0.001087 0.743995 0.928317
lru_fifo 32 0.016296 0.001087 0.757223 0.911181
lru_rand 32 0.016278 0.001087 0.771287 0.899801
rand 32 0.017586 0.001173 0.719603 0.888849
rand_fifo 32 0.017633 0.001171 0.701898 0.912015
rand_lru 32 0.01762 0.001171 0.68781 0.932473
fifo 64 0.00639 0.000479 0.686542 0.913393
fifo_lru 64 0.006389 0.000479 0.673001 0.922829
fifo_rand 64 0.00639 0.000479 0.699861 0.884465
lru 64 0.005923 0.000446 0.853641 0.999789
lru_el 64 0.005923 0.000446 0.853641 0.999789
lru_elr 64 0.005922 0.000446 0.853461 1
lru_fifo 64 0.00595 0.000446 0.733174 0.912532
lru_rand 64 0.00594 0.000446 0.7451 0.902349
rand 64 0.006615 0.000479 0.681471 0.885869
rand_fifo 64 0.006635 0.000483 0.662083 0.911556
rand_lru 64 0.006628 0.000483 0.64979 0.930711
0
0.2
0.4
0.6
0.8
1
1.2
Matrix Size 128
L1_D
L1_I
L2
L3
0
0.2
0.4
0.6
0.8
1
1.2
Matrix Size 64
L1_D
L1_I
L2
L3
fifo 128 0.01909 0.000086 0.07945 0.693392
fifo_lru 128 0.019127 0.000086 0.075329 0.755658
fifo_rand 128 0.019102 0.000086 0.081351 0.675566
lru 128 0.018813 0.00008 0.076337 0.731806
lru_el 128 0.018695 0.00008 0.085995 0.755884
lru_elr 128 0.018689 0.00008 0.065093 0.998414
lru_fifo 128 0.018768 0.00008 0.08044 0.722336
lru_rand 128 0.018784 0.00008 0.082309 0.680509
rand 128 0.017315 0.000087 0.090181 0.707026
rand_fifo 128 0.017325 0.000086 0.087353 0.69527
rand_lru 128 0.017355 0.000086 0.082081 0.737382
lru 256 0.018309 0.000011 0.99013 0.050849
lru_el 256 0.018376 0.000011 0.996695 0.520432
lru_elr 256 0.018314 0.000011 0.989714 0.524697
Changing the memory hierarchy / Cache exclusive
0
10
20
30
40
50
60
70
matrix_size L1_D L1_I L2 L3
Matrix Size -64
lru
lru_el
lru_elr
0
20
40
60
80
100
120
140
matrix_size L1_D L1_I L2 L3
Matrix Size - 128
lru
lru_el
lru_elr
0
50
100
150
200
250
300
matrix_size L1_D L1_I L2 L3
Matrix Size - 256
lru
lru_el
lru_elr
Reference
• Virtual Image -
https://drive.google.com/open?id=0B8K6cnetxNFmcXZ2R2lzMUptQWs
• http://www.ece.uah.edu/~milenka/docs/milenkovic_acmse04r. pdf
• http://www.cs.ucf.edu/~neslisah/final.pdf
• http://www.cse.scu.edu/~mwang2/projects/Cache_replacemen t_10s.pdf
• https://ece752.ece.wisc.edu/lect11-cache-replacement.pdf
• https://en.wikipedia.org/wiki/Cache_replacement_policies
• http://people.csail.mit.edu/emer/papers/2010.06.isca.rrip.pdf
• http://www.cs.utexas.edu/users/mckinley/papers/evict-me-pac t-2002.pdf
• http://snir.cs.illinois.edu/PDF/Temporal%20and%20Spatial%20L ocality.pdf
• https://math.mit.edu/~stevenj/18.335/ideal-cache.pdf
• https://pdfs.semanticscholar.org/6ebe/c8701893a6770eb0e19a 0d4a732852c86256.pdf • https://fD3hhNnfL6kwww.youtube.com/watch?v=
• http://pages.cs.wisc.edu/~david/courses/cs752/Spring2015/ge m5-tutorial/index.html
• http://blog.stuffedcow.net/2013/01/ivb-cache-replacement/
• https://github.com/dependablecomputinglab/csi3102-gem5-ne w-cache-policy
