On Tue, Jan 26, 2021 at 11:32:25AM -0500, John Kacur wrote:

Not necessarily, but you want to limit where the threads, no matter
how few or how many run. As I said, it's not an unreasonable default,
but it is not the current default of 1 unless you specify -t
I suggest we stick with the current default in this clean-up effort.
We can discuss if there are some better defaults after this effort is
complete.

Understood. BTW, you can do '-a 1 -t' which will spawn N threads on CPU
1. So it's still possible to get the same setup.

I haven't done a git bisect or something of that sort to determine if your
patches broke it, but here's what I see. (running on non-rt laptop now, so
ignore numbers), but it looks like at least the -t option requiring an
argument existed before your changes, but your changes to affinity
probably could use some more testing.

The following is okay

./signaltest  -a1-4
2.00 1.52 1.14 2/1079 6541

T: 0 ( 6537) P: 0 C:  14896 Min:      3 Act:    4 Avg:   26 Max:     366


The following is broken, the default without an argument should be 2
./signaltest  -t
./signaltest: option requires an argument -- 't'

Right, this shouldn't be too hard to fix. I'll send an update.

In the following note that threads other than thread 0 didn't appear
on the screen until after the ctrl-c

./signaltest -t9 -a1-4
1.11 1.14 1.14 2/1075 6864

T: 0 ( 6856) P: 0 C:   1649 Min:     38 Act:  511 Avg:  457 Max:    4911
^CT: 0 ( 6856) P: 0 C:   1660 Min:     38 Act:  554 Avg:  457 Max:    4911
T: 1 ( 6857) P: 0 C:   1660 Min:     38 Act:  490 Avg: 1090 Max:   15024
T: 2 ( 6858) P: 0 C:   1660 Min:     38 Act:  449 Avg: 1091 Max:   15053
T: 3 ( 6859) P: 0 C:   1660 Min:     38 Act:  412 Avg: 1091 Max:   15075
T: 4 ( 6860) P: 0 C:   1660 Min:     38 Act:  378 Avg: 1090 Max:   15081
T: 5 ( 6861) P: 0 C:   1659 Min:     38 Act:  517 Avg: 1091 Max:   15072
T: 6 ( 6862) P: 0 C:   1659 Min:     38 Act:  485 Avg: 1091 Max:   15067
T: 7 ( 6863) P: 0 C:   1659 Min:     38 Act:  522 Avg: 1091 Max:   12832
T: 8 ( 6864) P: 0 C:   1659 Min:     38 Act:  549 Avg: 1091 Max:   12839


etc, it's broken in many ways.

I don't think I broke this. This is since I can remember the output
behavior. You only see the live update from T0, never the from the
helper threads.