[PATCH 0/4] Add SCHED_BATCH and SCHED_IDLE support to chrt

[Denys Vlasenko]

On Sun, Jan 28, 2018 at 11:10 AM, walter harms <wharms at bfs.de> wrote:
>> On Wed, Jan 24, 2018 at 1:28 AM, Povilas Kanapickas <povilas at radix.lt> wrote:
>>>>> The following patches add SCHED_BATCH and SCHED_IDLE support to chrt.
>>>>> The priority limits are fixed to follow the specification. The last
>>>>> patch avoids hardcoding the values of SCHED_* macros as array indices.
>>>>> Perhaps counter-intuitively, this leads to binary size reduction of
>>>>> 90 bytes on x86-64. However the patch series as a whole still increase
>>>>> the binary size by 173 bytes on x86-64.
>>>>
>>>> Applied patches 1 and 2. Fixed a problem of patch 3 a bit differently.
>>>> Patch 4 increases the code, not applied.
>>>
>>> Thanks a lot.
>>>
>>> I'd like to know what I missed with regards to code size increase. Which
>>> architectures do you check the code size on? Is there anything else I
>>> should've known? Maybe the size of the text segment carries more weight
>>> than e.g. rodata or something similar?
>>
>> This may depend on toolchain and libc. In my test, with my toolchain,
>> it was not a win.
>
> Hi Denys,
> maybe i missed it somewhere but did you provide some numbers ?
> Did it grow for one byte or kilobytes ?

~40 bytes out of ~850 bytes in chrt.o

function                                             old     new   delta
get_policy_name                                        -      57     +57
show_min_max                                          59      64      +5
chrt_main                                            432     429      -3
policies                                              72       -     -72
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/1 up/down: 62/-75)            Total: -13 bytes
   text       data        bss        dec        hex    filename
 933375        481       6856     940712      e5aa8    busybox_old
 933417        481       6856     940754      e5ad2    busybox_unstripped