timing: Always split histogram with zero as a boundary

[smunaut]

If the timing histogram has both positive and negative numbers,
then we ensure that zero is used as a boundary and that at least
25% of the bins are dedicated to both positive and negative side
so you get a decent level of details on both sides.

Obviously that means bin size is different for positive / negative
sides.

Signed-off-by: Sylvain Munaut [email protected]

[eddiehung]

In principle, I think this is a good idea. Can you provide an example output?

Obviously that means bin size is different for positive / negative sides.

I'm not sure about this though, as it breaks the understanding that the area of each bar (excepting perhaps the two ends) are proportional to their frequency. Perhaps it is better to have two historgrams instead?

[smunaut]

Example output :

The * and + still mean the same of course, but the interval size in picosecond is different between the pos and neg bins.

And yeah, possibly two distinct histograms would make more sense this would also provide more granularity ...

Info: Slack histogram:
Info:  legend: * represents 24 endpoint(s)
Info:          + represents [1,24) endpoint(s)
Info: [ -2275,  -1820) |+
Info: [ -1820,  -1365) | 
Info: [ -1365,   -910) | 
Info: [  -910,   -455) | 
Info: [  -455,      0) |+
Info: [     0,   5216) |************************+
Info: [  5216,  10432) |*****+
Info: [ 10432,  15648) |********************+
Info: [ 15648,  20864) |***********************************+
Info: [ 20864,  26080) |************************************************************ 
Info: [ 26080,  31296) | 
Info: [ 31296,  36512) | 
Info: [ 36512,  41728) | 
Info: [ 41728,  46944) | 
Info: [ 46944,  52160) | 
Info: [ 52160,  57376) | 
Info: [ 57376,  62592) | 
Info: [ 62592,  67808) | 
Info: [ 67808,  73024) | 
Info: [ 73024,  78240) |+

[smunaut]

Just added a slightly different version that also prints exactly how many EPs are in there (in addition to the bar). I find it useful to check when I actually except a certain number of EP to fail to make sure only that # and not more are failing.

Info: Slack histogram:
Info:  legend: * represents 1 endpoint(s)
Info:          + represents [1,1) endpoint(s)
Info: [ -1390,  -1112) |      1 | * 
Info: [ -1112,   -834) |     10 | ********** 
Info: [  -834,   -556) |      2 | ** 
Info: [  -556,   -278) |      7 | ******* 
Info: [  -278,      0) |      0 |  
Info: [     0,    452) |      2 | ** 
Info: [   452,    904) |      1 | * 
Info: [   904,   1356) |      3 | *** 
Info: [  1356,   1808) |      5 | ***** 
Info: [  1808,   2260) |      2 | ** 
Info: [  2260,   2712) |      7 | ******* 
Info: [  2712,   3164) |     23 | *********************** 
Info: [  3164,   3616) |      8 | ******** 
Info: [  3616,   4068) |     10 | ********** 
Info: [  4068,   4520) |      6 | ****** 
Info: [  4520,   4972) |      6 | ****** 
Info: [  4972,   5424) |      5 | ***** 
Info: [  5424,   5876) |     56 | ******************************************************** 
Info: [  5876,   6328) |     21 | ********************* 
Info: [  6328,   6780) |      6 | ****** 

[smunaut]

@eddiehung feedback ?