Hello,
On (11/10/15 17:20), David Rientjes wrote:
>>On (11/10/15 22:32), Sergey Senozhatsky wrote:
>>
>> Build all of the $(TARGETS), not just the first one.
>>
>> Without the patch (make -n)
>> ==============================
>>
>> make -C ../lib/api
>> gcc -Wall -Wextra -I../lib/ -o page-types page-types.c ...
>>
>> Only 'page-types' target was built.
>>
>> With the patch (make -n)
>> ===========================
>>
>> make -C ../lib/api
>> gcc -Wall -Wextra -O2 -I../lib/ -o page-types page-types.c ...
>> gcc -Wall -Wextra -O2 -I../lib/ -o slabinfo slabinfo.c ...
>> gcc -Wall -Wextra -O2 -I../lib/ -o page_owner_sort page_owner_sort.c ...
>>
>> All 3 targets ('page-types', 'slabinfo', 'page_owner_sort') were
>> built.
>>
>> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
>> ---
>
> This doesn't purport to explain why -O2 was added or why it's needed for←
> these tools.
Hm, that was a sem-automatic action I saw no issues with (besides, I
considered this to be too small for a separate patch). `slabinfo' can
be used to collected extended '-X' measurements for gnuplot script
e.g.
`while [ 1 ]; do slabinfo -X >> stats; sleep 0.1s; done`
so making it a bit lighter is sort of positive change, though I'm not
married to this option.
perf stats:
-- OLD
Performance counter stats for './slabinfo.old -X -B -N 100':
197.879348 task-clock (msec) # 0.969 CPUs utilized
22 context-switches # 0.111 K/sec
0 cpu-migrations # 0.000 K/sec
2,276 page-faults # 0.012 M/sec
182,916,015 cycles # 0.924 GHz
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
259,843,733 instructions # 1.42 insns per cycle
53,949,755 branches # 272.640 M/sec
157,607 branch-misses # 0.29% of all branches
0.204190648 seconds time elapsed
-- NEW (-O2)
Performance counter stats for './slabinfo.new -X -B -N 100':
169.963546 task-clock (msec) # 0.977 CPUs utilized
9 context-switches # 0.053 K/sec
0 cpu-migrations # 0.000 K/sec
2,276 page-faults # 0.013 M/sec
153,582,826 cycles # 0.904 GHz
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
218,505,232 instructions # 1.42 insns per cycle
45,410,422 branches # 267.177 M/sec
114,126 branch-misses # 0.25% of all branches
0.173921887 seconds time elapsed
./scripts/bloat-o-meter tools/vm/slabinfo.old tools/vm/slabinfo.new
add/remove: 5/23 grow/shrink: 7/7 up/down: 6434/-9495 (-3061)
function old new delta
main 878 3699 +2821
output_slabs 307 2075 +1768
report 781 1905 +1124
rename_slabs 167 333 +166
read_slab_obj.isra - 131 +131
ops.isra - 104 +104
set_obj.isra - 102 +102
read_obj 145 236 +91
sort_slabs 414 478 +64
slab_empty.part - 32 +32
get_obj.part - 17 +17
slab_numa 542 556 +14
decode_numa_list 235 230 -5
fatal 176 160 -16
usage 17 - -17
onoff 27 - -27
show_tracking 193 162 -31
get_obj_and_str 157 124 -33
slab_size 43 - -43
slab_mismatch 47 - -47
get_obj 48 - -48
slab_waste 56 - -56
link_slabs 226 169 -57
slab_activity 60 - -60
slab_validate 63 - -63
slab_shrink 63 - -63
slab_empty 74 - -74
first_line 74 - -74
store_size 271 191 -80
xtotals 142 - -142
ops 145 - -145
set_obj 162 - -162
read_slab_obj 182 - -182
find_one_alias 187 - -187
sort_aliases 288 - -288
alias 298 - -298
debug_opt_scan 355 - -355
slab_debug 870 - -870
totals 4136 3198 -938
slabcache 1289 - -1289
read_slab_dir 1798 - -1798
slab_stats 2047 - -2047
I believe the remaining tools will not `suffer' as well.
Do you prefer to remove -O2?
-ss
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