On Fri, 10 Feb 2023 at 17:05, Roberto A. Foglietta <
roberto.foglietta@gmail.com> wrote:

> On Wed, 25 Jan 2023 at 05:48, Roberto A. Foglietta <
> roberto.foglietta@gmail.com> wrote:
>
>> On Thu, 19 Jan 2023 at 19:08, Roberto A. Foglietta
>
>
SSTATE CACHE REWORK + APT CACHE MOUNT BIND
==========================================

Debug code is still in place but the APT cache and lists are offered by
binding.
Binding is the favourite way to offer APT cache and repositories lists but
not
with sbuild because the lock contention is not supported with binding. It is
using soft links but in an improved declination.

        devel4 (public) + npriv12 (private)
       ------------------------------------
            fresh              cache
       ------------ complete --------------
       32417 Mb (max)   | 27740 Mb (max)
       23294 Mb (rest)  | 18657 Mb (rest)
        4283 Mb (deb)   |  4283 Mb (deb)
        8989 Mb (wic)   |  8987 Mb (wic) <-- cache!
        4398 Mb (cache) |  4398 Mb (cache)
       time: 12m01s     | time:  2m30s [*]   4.81x
       ------------ original ---------------------
       time: 21m17s     | time:  8m28s
              1.77x              3.39x

        devel4 (public) + npriv12 (private)
       ------------------------------------
            fresh              cache
       ------------ basic-os --------------
        3946 Mb (max)   |  3176 Mb (max)
        2976 Mb (rest)  |  2278 Mb (rest)
        4283 Mb (deb)   |  4283 Mb (deb)
         803 Mb (wic)   |   802 Mb (wic) <-- cache!
         520 Mb (cache) |   520 Mb (cache)
       time:  3m05s     | time:    20s       9.25x
       ------------ original ---------------------
       time:  7m58s     | time:  2m17s
              2.58x              6.85x

These numbers show that Ilbers' ISAR improved a lot during the time

    original, fresh                     21m17s
    complete, next, devel3, fresh       16m49s   1.27x
    complete, next.plus, devel3, fresh  15m49s   1.35x
    complete, npriv.12, devel4, fresh   12m01s   1.77x

    original, cache                      8m28s
    complete, next, devel3, cache        5m15s   1.61x
    complete, next.plus, devel3, cache   3m18s   2.57x
    complete, npriv.12, devel4, cache    2m30s   3.39x

For completeness: next.plus is the next with all the patches applied from
the
mailing list, all those patches that are supposed to improve the building
speed.

Considering that the nvidia-modules compilation takes 2m4s and producing
the wic
image takes 2m8s in the complete build but these activities are not part of
the
optimisation, we have these numbers:

    original, fresh                     17m05s
    complete, next, devel3, fresh       12m37s   1.35x
    complete, next.plus, devel3, fresh  11m37s   1.48x
    complete, npriv.12, devel4, fresh    7m49s   2.19x

    original, cache                      6m20s
    complete, next, devel3, cache        3m07s   2.03x
    complete, next.plus, devel3, cache   1m10s   5.43x
    complete, npriv.12, devel4, cache    0m22s  17.27x

The last number 22s is coherent with the basic-os cached building time.

[*] after 2m the complete fresh build, SSD needs to relax internally which
is
    fully acceptable in a real-case scenario. The original time values are
still
    correct because at the time they have been taken there was not a script
that
    immediately after the complete build was started the cached building.