Bug 1748965

This could be handled more generic way to allow future extensions - e.g. to support matching similar what the 'recommend.conf' allows.

Current proposal is to extend plugin instances matching of uname_regex and cpuinfo_regex, e.g.:

[variables]
cannonalake_cpuinfo=.*\bREGEX1\b.*
cannonlake_uname=REGEX2

[cpu_cannonlake]
type=cpu
cpuinfo_regex=${cannonlake_cpuinfo}
uname_regex=${cannonlake_uname}
force_latency=C1

[diks_cannonlake]
type=disk
cpuinfo_regex=${cannonlake_cpuinfo}
uname_regex=${cannonlake_uname}
readahead=4092

...

And also addition of operator for conditional includes of subprofiles for specific HW, e.g.:

[main]
include=${cpu:${cannonlake_cpuinfo}:file_cannonlake.conf:other.conf}

[variables]
cannonalake_cpuinfo=.*\bREGEX1\b.*

(In reply to Jaroslav Škarvada from comment #5)
> And also addition of operator for conditional includes of subprofiles for
> specific HW, e.g.:
> 
> [main]
> include=${cpu:${cannonlake_cpuinfo}:file_cannonlake.conf:other.conf}
> 
> [variables]
> cannonalake_cpuinfo=.*\bREGEX1\b.*

Current proposal for the second feature (fallback_profile will be used when nothing matches, it's optional):

[main]
include=${cpuinfo:${cannonlake_cpuinfo_regex}:cannonlake_tuned_profile:$(cascadelake_cpuinfo_regex}:cascadelake_tuned_profile:...:fallback_profile}

[variables]
cannonalake_cpuinfo_regex=.*\bREGEX_CANNONLAKE\b.*
cascadelake_cpuinfo_regex=.*\bREGEX_CASCADELAKE\b.*
...

It's also possible to combine it with the base profile, the following loads base_tuned_profile and adds specific CPU profile on top of it:

[main]
include=base_tuned_profile,${cpuinfo:${cannonlake_cpuinfo_regex}:cannonlake_tuned_profile:$(cascadelake_cpuinfo_regex}:cascadelake_tuned_profile}

Upstream PR:
https://github.com/redhat-performance/tuned/pull/218

It's possible to write now:

[variables]
cannonalake_cpuinfo=.\bGenuineIntel\b.
cannonlake_uname=x86_64

[cpu_cannonlake]
type=cpu
cpuinfo_regex=${cannonlake_cpuinfo}
uname_regex=${cannonlake_uname}
force_latency=C1

[disk_cannonlake]
type=disk
cpuinfo_regex=${cannonlake_cpuinfo}
uname_regex=${cannonlake_uname}
readahead=4092

...

And the tuning will be applied only on machines which have
'GenuineIntel' string in the /proc/cpuinfo and x86_64 architecture (from
uname). Both 'cpuinfo_regex' and 'uname_regex' are optional - if not
used it has the same effect as if matching regex is used. This example
used variables but it also works without it.

Also cpuinfo_check builtin function was added, so it's possible to write
the following now:

[main]
include=${f:cpuinfo_check:\bGenuineIntel\b:intel_profile:other_profile}

It tries to match the regex '\bGenuineIntel\b' in the /proc/cpuinfo
and if it matches it includes 'intel_profile', if not it includes
'other_profile'. If colon ':' needs to be used in the regex, it needs
to be escaped, i.e.: ':'

It's even possible to combine it with the generic profiles, e.g.:
[main]
include=base_profile${f:cpuinfo_check:\bGenuineIntel\b:,intel_profile}

It will always include 'base_profile' and if the cpuinfo matches
GenuineIntel it also adds the intel_profile. More variants are possible,
the generic syntax is:

${f:cpuinfo_check:REGEX1:STR1:REGEX2:STR2,...[,FALLBACK_STR]}

It returns STR1 if REGEX1 matches, STR2 if REGEX2 matches, and
FALLBACK_STR if nothing matches. If there is no FALLBACK_STR it returns
empty string on no match. It exits on the first match found and
no more regexes are processed in such case

TODO:
Current limitation: Variables are not expanded in the include, so it's
not possible to write:

[main]
include=${f:cpuinfo_check:${regex}:test}

[variables]
regex=TEST

(In reply to Jaroslav Škarvada from comment #7)
> It will always include 'base_profile' and if the cpuinfo matches
> GenuineIntel it also adds the intel_profile. More variants are possible,
> the generic syntax is:
> 
> ${f:cpuinfo_check:REGEX1:STR1:REGEX2:STR2,...[,FALLBACK_STR]}
> 
Typo, it should be:
${f:cpuinfo_check:REGEX1:STR1:REGEX2:STR2:...[:FALLBACK_STR]}

Just to be clear the example in comment 7 is just synthetic to demonstrate the feature and it will not match Cannonlake CPUs. It matches any x86_64 Intel CPU. For Cannonlake matching correct CPU/model regexes needs to be supplied instead of the generic regex used.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:1883