Preconditioning doesn't work properly.

[SAM-ZY-2019]

I think the preconditioning doesn’t work – endless while loop. In FTL.cpp, FTL::Perform_precondition function, Step 1-4, there are two while loops:

while (lpa_set_for_preconditioning.size() < no_of_logical_pages_in_steadystate)
                           {
                                  … cout<<loop1
                                  {
                                         … cout<<loop2

The “loop1” runs forever, and the printouts of it show that "lpa_set_for_preconditioning" is always an empty set. In detail, [FTL::Perform_precondition] Step 1-4: while loop 1:

lpa_set_for_preconditioning.size()=0 <  no_of_logical_pages_in_steadystate=43687868.

[arashta]

Preconditioning has been working correctly for all of our simulation scenarios. Please share the SSD configuration and workload definition files you are using for your simulation scenarios.

[SAM-ZY-2019]

Error: Unhandled address distribution type in FTL's preconditioning function. SSD: `<?xml version="1.0" encoding="us-ascii"?>

1.00000 4 400000 false 1000000 321 true FLASH NVME 65535 16 ADVANCED SHARED 268435456 8192 400 2 13 13 13 HYBRID true 2097152 SHARED CWDP OUT_OF_ORDER 0.07 0.05000 RGA false false 0.005000 true true 100 700000 700000 100000 2 1 333 4 NVDDR2 MLC ERASE 75000 75000 75000 750000 750000 750000 3800000 10000 700000 100000 2 2 2048 256 8192 448

Trace-based Workload <?xml version="1.0" encoding="us-ascii"?>

HIGH WRITE_CACHE 0,1 0,1,2,3 0,1 0,1 70 traces/tpcc-small.trace 100 1 NANOSECOND

`

[zinechant]

It seems if the workload is trace-only, the Address_Distribution_Type is by default set as MIXED_STREAMING_RANDOM, which is not handled in preconditioning. One workaround seems to be changing the enum definition of Address_Distribution_Type to use a type handled by preconditioning as default.