First version of file allocation perf measuring program

This program measures performance of creating a file and zeroing it using
a few different methods:

1. using the posix_fallocate() syscall
2. using mmap() and then memset()
3. writing chunks to the file (currently 4k and 8k-sized chunks)

directly calling the Linux fallocate() syscall doesn't yet work; a bug has
been filed earlier for this in the Red Hat Bugzilla, #485487

A few results from running this program on my laptop and on my desktop are put
in the results.txt file.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

1 files changed, 257 insertions, 0 deletions

diff --git a/results.txt b/results.txt
new file mode 100644
index 0000000..3618ec5
--- /dev/null
+++ b/results.txt
@@ -0,0 +1,257 @@
+-- These tests conducted on a laptop --
+
+1st run, with only posix-fallocate on ext3
+$ ./test-file-zero-speed
+seconds:microseconds: 1235557175:156446
+seconds:microseconds: 1235557212:186703
+
+-------------------------------------------------------------------
+
+2nd run, same program as above
+$ ./test-file-zero-speed
+seconds:microseconds: 1235557363:187840
+seconds:microseconds: 1235557396:43475
+
+-------------------------------------------------------------------
+
+3rd run, same program (with no printf between gtod() and actual call)
+$ ./test-file-zero-speed
+posix-fallocate run time:
+      seconds:microseconds: 1235558782:292459
+      seconds:microseconds: 1235558816:331028
+      (approx 34s)
+$ sudo filefrag ../tmp/10gfile-pf
+../tmp/10gfile-pf: 134 extents found, perfection would be 9 extents
+
+-------------------------------------------------------------------
+
+With all three:
+$ ./test-file-zero-speed
+posix-fallocate run time:
+      seconds:microseconds: 1235569716:953548
+      seconds:microseconds: 1235569749:595276
+      (approx 33s)
+mmap run time:
+      seconds:microseconds: 1235569749:595577
+      seconds:microseconds: 1235569789:622942
+      (approx 40s)
+4096-sized chunk run time:
+      seconds:microseconds: 1235569791:134534
+      seconds:microseconds: 1235569839:132586
+      (approx 48s)
+$ sudo filefrag ../tmp/*
+../tmp/file-chunk: 57 extents found, perfection would be 9 extents
+../tmp/file-mmap: 106 extents found, perfection would be 9 extents
+../tmp/file-pf: 132 extents found, perfection would be 9 extents
+
+-------------------------------------------------------------------
+
+Added free(), 8k-chunk, close(fd) in time calculation
+
+$ free -m                                            
+             total       used       free     shared    buffers     cached
+Mem:          1954        859       1095          0          7        388
+-/+ buffers/cache:        462       1491                                 
+Swap:         4094        742       3351                                 
+$ ./test-file-zero-speed                             
+posix-fallocate run time:                                                
+        seconds:microseconds: 1235571071:797642                          
+       seconds:microseconds: 1235571104:428998                          
+       (approx 33s)                                                     
+mmap run time:                                                           
+       seconds:microseconds: 1235571104:429523                          
+       seconds:microseconds: 1235571147:770146                          
+       (approx 43s)                                                     
+4096-sized chunk run time:                                               
+       seconds:microseconds: 1235571149:318119                          
+       seconds:microseconds: 1235571187:731919                          
+       (approx 38s)                                                     
+8192-sized chunk run time:                                               
+       seconds:microseconds: 1235571189:614692                          
+       seconds:microseconds: 1235571228:355714                          
+       (approx 39s)                                                     
+$ free -m                                            
+            total       used       free     shared    buffers     cached
+Mem:          1954        853       1101          0          1        415
+-/+ buffers/cache:        436       1517                                 
+Swap:         4094        742       3351                                 
+$ sudo filefrag ../tmp/*                             
+[sudo] password for amit:                                                
+../tmp/file-chunk4: 60 extents found, perfection would be 9 extents      
+../tmp/file-chunk8: 86 extents found, perfection would be 9 extents      
+../tmp/file-mmap: 117 extents found, perfection would be 9 extents       
+../tmp/file-pf: 133 extents found, perfection would be 9 extents
+
+-------------------------------------------------------------------
+
+
+-- These tests conducted on a desktop --
+
+$ sudo ./test-file-zero-speed /mnt/btrfs/
+posix-fallocate run time:
+       seconds:microseconds: 1235757533:559903
+       seconds:microseconds: 1235757533:560119
+       (approx 0s)
+mmap run time:
+       seconds:microseconds: 1235757533:564220
+       seconds:microseconds: 1235757551:589402
+       (approx 18s)
+4096-sized chunk run time:
+       seconds:microseconds: 1235757552:688346
+       seconds:microseconds: 1235757572:585343
+       (approx 20s)
+8192-sized chunk run time:
+       seconds:microseconds: 1235757576:143821
+       seconds:microseconds: 1235757592:424030
+       (approx 16s)
+
+-------------------------------------------------------------------
+
+sudo ./test-file-zero-speed /mnt/ext4/
+posix-fallocate run time:
+       seconds:microseconds: 1235757627:972541
+       seconds:microseconds: 1235757642:159940
+       (approx 15s)
+mmap run time:
+       seconds:microseconds: 1235757643:901565
+       seconds:microseconds: 1235757646:690830
+       (approx 3s)
+4096-sized chunk run time:
+       seconds:microseconds: 1235757647:879737
+       seconds:microseconds: 1235757668:701027
+       (approx 21s)
+8192-sized chunk run time:
+       seconds:microseconds: 1235757670:722389
+       seconds:microseconds: 1235757686:780528
+       (approx 16s)
+
+-------------------------------------------------------------------
+[ 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
+
+-------------------------------------------------------------------
+
+[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
+
+-------------------------------------------------------------------
+$ 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
+-------------------------------------------------------------------
+$ 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
+...
+-------------------------------------------------------------------
+-------------------------------------------------------------------