Backport computing of resolver tasks from count of cpus

Previously bind had 523 tasks when large tunning was used.
With this change users with small servers will be able to
benefit from dynamically computed count of tasks and users with
big servers will not encounter any change unless they will
manually override thread count with -n option.

Fix #1693
78 jobs for !4245 with 1693-backport-dynamic-ntask-computing in 11 minutes and 57 seconds (queued for 8 seconds)
latest detached
Status Job ID Name Coverage
  Precheck
passed #1208312
amd64 linux
autoreconf

00:00:21

passed #1208314
amd64 linux
clang-format

00:00:13

passed #1208315
amd64 linux
coccinelle

00:01:01

passed #1208313
amd64 linux
misc

00:00:20

 
  Build
passed #1208330
amd64 linux
clang:asan

00:04:57

passed #1208334
amd64 linux
clang:buster:amd64

00:02:31

passed #1208336
amd64 libvirt
clang:freebsd11:amd64

00:02:05

passed #1208337
amd64 libvirt
clang:freebsd12:amd64

00:01:41

passed #1208338
amd64 libvirt
clang:openbsd:amd64

00:03:48

passed #1208332
amd64 linux
clang:tsan

00:02:54

passed #1208316
amd64 linux
gcc:alpine3.12:amd64

00:01:48

passed #1208329
amd64 linux
gcc:asan

00:03:18

passed #1208321
amd64 linux
gcc:buster:amd64

00:02:04

passed #1208317
amd64 linux
gcc:centos6:amd64

00:01:46

passed #1208318
amd64 linux
gcc:centos7:amd64

00:01:59

passed #1208319
amd64 linux
gcc:centos8:amd64

00:02:07

passed #1208326
amd64 linux
gcc:fedora32:amd64

00:02:09

passed #1208328
amd64 linux
gcc:focal:amd64

00:02:12

passed #1208333
amd64 linux
gcc:mutexatomics

00:02:05

passed #1208323
amd64 linux
gcc:out-of-tree

00:02:13

passed #1208335
amd64 linux
gcc:pkcs11

00:02:13

passed #1208322
amd64 linux
gcc:sid:amd64

00:02:52

passed #1208324
i386 linux
gcc:sid:i386

00:02:17

passed #1208320
amd64 linux
gcc:stretch:amd64

00:02:31

passed #1208331
amd64 linux
gcc:tsan

00:02:25

passed #1208325
amd64 linux
gcc:tumbleweed:amd64

00:02:05

passed #1208327
amd64 linux
gcc:xenial:amd64

00:02:20

passed #1208340
amd64 windows
msvc:windows:amd64

00:00:59

passed #1208339
amd64 linux
nolibtool:sid:amd64

00:03:00

 
  Unit
passed #1208354
amd64 linux
unit:clang:asan

00:01:21

passed #1208358
amd64 linux
unit:clang:buster:amd64

00:00:26

passed #1208360
amd64 libvirt
unit:clang:freebsd11:amd64

00:01:08

passed #1208361
amd64 libvirt
unit:clang:freebsd12:amd64

00:00:57

passed #1208356
amd64 linux
unit:clang:tsan

00:04:14

passed #1208341
amd64 linux
unit:gcc:alpine3.12:amd64

00:00:39

passed #1208353
amd64 linux
unit:gcc:asan

00:01:13

passed #1208346
amd64 linux
unit:gcc:buster:amd64

00:00:34

passed #1208342
amd64 linux
unit:gcc:centos6:amd64

00:00:41

passed #1208343
amd64 linux
unit:gcc:centos7:amd64

00:00:41

passed #1208344
amd64 linux
unit:gcc:centos8:amd64

00:00:33

passed #1208350
amd64 linux
unit:gcc:fedora32:amd64

00:00:36

passed #1208352
amd64 linux
unit:gcc:focal:amd64

00:00:45

passed #1208357
amd64 linux
unit:gcc:mutexatomics

00:00:34

passed #1208359
amd64 linux
unit:gcc:pkcs11

00:00:38

passed #1208347
amd64 linux
unit:gcc:sid:amd64

00:00:32

passed #1208348
i386 linux
unit:gcc:sid:i386

00:00:39

passed #1208345
amd64 linux
unit:gcc:stretch:amd64

00:00:36

passed #1208355
amd64 linux
unit:gcc:tsan

00:05:09

passed #1208349
amd64 linux
unit:gcc:tumbleweed:amd64

00:00:36

passed #1208351
amd64 linux
unit:gcc:xenial:amd64

00:00:34

passed #1208362
amd64 linux
unit:nolibtool:sid:amd64

00:00:49

 
  System
passed #1208376
amd64 linux
system:clang:asan

00:06:28

passed #1208380
amd64 linux
system:clang:buster:amd64

00:05:18

passed #1208382
amd64 libvirt
system:clang:freebsd11:amd64

00:08:07

passed #1208383
amd64 libvirt
system:clang:freebsd12:amd64

00:08:10

passed #1208378
amd64 linux
system:clang:tsan

00:08:00

passed #1208363
amd64 linux
system:gcc:alpine3.12:amd64

00:05:28

passed #1208375
amd64 linux
system:gcc:asan

00:06:36

passed #1208368
amd64 linux
system:gcc:buster:amd64

00:05:14

passed #1208364
amd64 linux
system:gcc:centos6:amd64

00:05:37

passed #1208365
amd64 linux
system:gcc:centos7:amd64

00:05:09

passed #1208366
amd64 linux
system:gcc:centos8:amd64

00:05:15

passed #1208372
amd64 linux
system:gcc:fedora32:amd64

00:05:19

passed #1208374
amd64 linux
system:gcc:focal:amd64

00:05:22

passed #1208379
amd64 linux
system:gcc:mutexatomics

00:05:23

passed #1208381
amd64 linux
system:gcc:pkcs11

00:06:06

passed #1208369
amd64 linux
system:gcc:sid:amd64

00:05:07

passed #1208370
i386 linux
system:gcc:sid:i386

00:05:19

passed #1208367
amd64 linux
system:gcc:stretch:amd64

00:05:04

passed #1208377
amd64 linux
system:gcc:tsan

00:08:51

passed #1208371
amd64 linux
system:gcc:tumbleweed:amd64

00:05:16

passed #1208373
amd64 linux
system:gcc:xenial:amd64

00:05:12

passed #1208384
amd64 linux
system:nolibtool:sid:amd64

00:05:14

 
  Docs
passed #1208385
amd64 linux
docs

00:00:28

 
  Postcheck
passed #1208389
amd64 linux
cppcheck

00:00:40

passed #1208386
amd64 linux
flake8

00:00:43

passed #1208387
amd64 linux
pylint

00:00:44

passed #1208388
amd64 linux
scan-build

00:09:42