tools/vm/slabinfo: use getopt no_argument/optional_argument

tools/vm/slabinfo: use getopt no_argument/optional_argument

This patchset adds 'extended' slabinfo mode that provides additional
information:

 -- totals summary
 -- slabs sorted by size
 -- slabs sorted by loss (waste)

The patches also introduces several new slabinfo options to limit the
number of slabs reported, sort slabs by loss (waste); and some fixes.

Extended output example (slabinfo -X -N 2):

 Slabcache Totals
 ----------------
 Slabcaches :              91   Aliases  :         119->69   Active:     63
 Memory used:       199798784   # Loss   :        10689376   MRatio:     5%
 # Objects  :          324301   # PartObj:           18151   ORatio:     5%

 Per Cache         Average              Min              Max            Total
 ----------------------------------------------------------------------------
 #Objects             5147                1            89068           324301
 #Slabs                199                1             3886            12537
 #PartSlab              12                0              240              778
 %PartSlab             32%               0%             100%               6%
 PartObjs                5                0             4569            18151
 % PartObj             26%               0%             100%               5%
 Memory            3171409             8192        127336448        199798784
 Used              3001736              160        121429728        189109408
 Loss               169672                0          5906720         10689376

 Per Object        Average              Min              Max
 -----------------------------------------------------------
 Memory                585                8             8192
 User                  583                8             8192
 Loss                    2                0               64

 Slabs sorted by size
 --------------------
 Name                   Objects Objsize           Space Slabs/Part/Cpu  O/S O %Fr %Ef Flg
 ext4_inode_cache         69948    1736       127336448      3871/0/15   18 3   0  95 a
 dentry                   89068     288        26058752      3164/0/17   28 1   0  98 a

 Slabs sorted by loss
 --------------------
 Name                   Objects Objsize            Loss Slabs/Part/Cpu  O/S O %Fr %Ef Flg
 ext4_inode_cache         69948    1736         5906720      3871/0/15   18 3   0  95 a
 inode_cache              11628     864          537472        642/0/4   18 2   0  94 a

The last patch in the series addresses Linus' comment from
http://marc.info/?l=linux-mm&m=144148518703321&w=2

(well, it's been some time. sorry.)

gnuplot script takes the slabinfo records file, where every record is a `slabinfo -X'
output. So the basic workflow is, for example, as follows:

        while [ 1 ]; do slabinfo -X -N 2 >> stats; sleep 1; done
        ^C
        slabinfo-gnuplot.sh stats

The last command will produce 3 png files (and 3 stats files)
-- graph of slabinfo totals
-- graph of slabs by size
-- graph of slabs by loss

It's also possible to select a range of records for plotting (a range of collected
slabinfo outputs) via `-r 10,100` (for example); and compare totals from several
measurements (to visially compare slabs behaviour (10,50 range)) using
pre-parsed totals files:
        slabinfo-gnuplot.sh -r 10,50 -t stats-totals1 .. stats-totals2

This also, technically, supports ktest. Upload new slabinfo to target,
collect the stats and give the resulting stats file to slabinfo-gnuplot

This patch (of 8):

Use getopt constants in `struct option' ->has_arg instead of numerical
representations.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>