[build] libsairedis takes 1.5h to build (used to be 3-4 min in the past)

[stepanblyschak]

Description

Steps to reproduce the issue:

1. make -f slave.mk target/debs/bullseye/libsairedis_1.0.0_amd64.deb

Describe the results you received:

It takes 1.5h to build

Describe the results you expected:

202019/202012 libsairedis can be built in 3-4 minutes.

Output of show version:

14012cf (master)

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[saiarcot895]

Could you elaborate on where you're seeing the 1.5-hour build time? The most recent commit in sairedis was built in 25 minutes, which is still high, IMO, but much less than 1.5 hours.

[saiarcot895]

Could you also check to see if sonic-net/sonic-sairedis#1194 results in any improvement? Note that testing this PR as part of the full sonic build will require some additional changes (specifically, the build profiles will need to be set instead of build targets).

[stepanblyschak]

@saiarcot895 I am not measuring CI build, if I do make -f slave.mk target/debs/bullseye/libsairedis_1.0.0_amd64.deb once all dependencies of libsairedis are compiled it takes for me almost 1.5 h

[saiarcot895]

It appears that SWIG 4.0 is resulting in a large time increase to compile the C++ files that it generates, compared to SWIG 3.0 (in Buster). The changes in sonic-net/sonic-sairedis#1194 should cut down the time significantly from 1.5 hours (I'm estimating it should go down to 30 minutes), but it won't be the same as what it was with SWIG 3.0.

Edit: Either SWIG 4.0 or gcc is causing the compilation time increase; I'm leaning towards SWIG 4.0, since this scale of time increase doesn't appear to be present in other builds.

[mikeberesford]

We are seeing an increase in sairedis build time after migrating to 202211 that may be related here as well - our local builds went from ~25 mins to ~50 mins, which appears to be mostly time spent in SWIG.