[ Extents were not enabled]

$ sudo ./test-file-zero-alloc-speed /mnt/ext4
posix-fallocate run time:
        seconds:microseconds: 1235977123:542643
        seconds:microseconds: 1235977137:673307
        (approx 14s)
mmap run time:
        seconds:microseconds: 1235977137:673494
        seconds:microseconds: 1235977154:435404
        (approx 17s)
4096-sized chunk run time:
        seconds:microseconds: 1235977155:826068
        seconds:microseconds: 1235977173:98883
        (approx 18s)
8192-sized chunk run time:
        seconds:microseconds: 1235977174:91821
        seconds:microseconds: 1235977190:862035
        (approx 16s)

$ sudo filefrag /mnt/ext4/*
/mnt/ext4/file-chunk4: 292 extents found, perfection would be 9 extents
/mnt/ext4/file-chunk8: 282 extents found, perfection would be 9 extents
/mnt/ext4/file-mmap: 295 extents found, perfection would be 9 extents
/mnt/ext4/file-pf: 279 extents found, perfection would be 9 extents

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[After enabling extents]
$ sudo ./test-file-zero-alloc-speed /mnt/ext4
posix-fallocate run time:
        seconds:microseconds: 1235979104:790662
        seconds:microseconds: 1235979104:848372
        (approx 0s)
mmap run time:
        seconds:microseconds: 1235979105:33407
        seconds:microseconds: 1235979118:535711
        (approx 13s)
4096-sized chunk run time:
        seconds:microseconds: 1235979120:297221
        seconds:microseconds: 1235979135:520910
        (approx 15s)
8192-sized chunk run time:
        seconds:microseconds: 1235979135:639915
        seconds:microseconds: 1235979153:502270
        (approx 18s)

$ sudo filefrag /mnt/ext4/*
File is stored in extents format
/mnt/ext4/file-chunk4: 29 extents found
File is stored in extents format
/mnt/ext4/file-chunk8: 20 extents found
File is stored in extents format
/mnt/ext4/file-mmap: 38 extents found
File is stored in extents format
/mnt/ext4/file-pf: 1 extent found

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$ sudo ./test-file-zero-alloc-speed /mnt/xfs/
posix-fallocate run time:
        seconds:microseconds: 1235977241:411119
        seconds:microseconds: 1235977241:469611
        (approx 0s)
mmap run time:
        seconds:microseconds: 1235977241:469981
        seconds:microseconds: 1235977255:687663
        (approx 14s)
4096-sized chunk run time:
        seconds:microseconds: 1235977256:603450
        seconds:microseconds: 1235977274:549963
        (approx 18s)
8192-sized chunk run time:
        seconds:microseconds: 1235977274:649325
        seconds:microseconds: 1235977293:365759
        (approx 19s)

$ sudo filefrag /mnt/xfs/*
/mnt/xfs/file-chunk4: 3 extents found
/mnt/xfs/file-chunk8: 4 extents found
/mnt/xfs/file-mmap: 2 extents found
/mnt/xfs/file-pf: 1 extent found
-------------------------------------------------------------------
$ sudo ./test-file-zero-alloc-speed /mnt/ext3/
posix-fallocate run time:
        seconds:microseconds: 1235977308:469496
        seconds:microseconds: 1235977326:366806
        (approx 18s)
mmap run time:
        seconds:microseconds: 1235977326:367325
        seconds:microseconds: 1235977346:260276
        (approx 20s)
4096-sized chunk run time:
        seconds:microseconds: 1235977347:161513
        seconds:microseconds: 1235977369:771397
        (approx 22s)
8192-sized chunk run time:
        seconds:microseconds: 1235977369:865221
        seconds:microseconds: 1235977393:23403
        (approx 24s)

$ sudo filefrag /mnt/ext3/*
/mnt/ext3/file-chunk4: 38 extents found, perfection would be 9 extents
/mnt/ext3/file-chunk8: 9 extents found
/mnt/ext3/file-mmap: 44 extents found, perfection would be 9 extents
/mnt/ext3/file-pf: 9 extents found
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$ sudo ./test-file-zero-alloc-speed /mnt/btrfs/
posix-fallocate run time:
        seconds:microseconds: 1235977416:649716
        seconds:microseconds: 1235977416:650009
        (approx 0s)
mmap run time:
        seconds:microseconds: 1235977416:650118
        seconds:microseconds: 1235977434:626664
        (approx 18s)
4096-sized chunk run time:
        seconds:microseconds: 1235977435:634000
        seconds:microseconds: 1235977452:208026
        (approx 17s)
8192-sized chunk run time:
        seconds:microseconds: 1235977452:294473
        seconds:microseconds: 1235977471:143672
        (approx 19s)

$ sudo /mnt/btrfs/*
FIBMAP: Invalid argument
...
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