Re: [PATCH v11 1/4] perf check: introduce check subcommand

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Fri, Jun 28, 2024 at 11:15:57AM -0300, Arnaldo Carvalho de Melo wrote:
> On Fri, Jun 28, 2024 at 11:12:16AM -0300, Arnaldo Carvalho de Melo wrote:
> > On Thu, Jun 27, 2024 at 03:36:41PM +0530, Aditya Gupta wrote:
> > > Currently the presence of a feature is checked with a combination of
> > > perf version --build-options and greps, such as:
> > > 
> > >     perf version --build-options | grep " on .* HAVE_FEATURE"
> > > 
> > > Instead of this, introduce a subcommand "perf check feature", with which
> > > scripts can test for presence of a feature, such as:
> > > 
> > >     perf check feature HAVE_FEATURE
> > > 
> > > 'perf check feature' command is expected to have exit status of 0 if
> > > feature is built-in, and 1 if it's not built-in or if feature is not known.
> > > 
> > > Multiple features can also be passed as a comma-separated list, in which
> > > case the exit status will be 1 only if all of the passed features are
> > > built-in. For example, with below command, it will have exit status of 0
> > > only if both libtraceevent and bpf are enabled, else 1 in all other cases
> > > 
> > >     perf check feature libtraceevent,bpf
> > > 
> > > The arguments are case-insensitive.
> > > An array 'supported_features' has also been introduced that can be used by
> > > other commands like 'perf version --build-options', so that new features
> > > can be added in one place, with the array
> 
> Now testing it with just this first patch applied:
> 
> ⬢[acme@toolbox perf-tools-next]$ perf check feature bpf
>                    bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
> ⬢[acme@toolbox perf-tools-next]$ echo $?
> 0
> ⬢[acme@toolbox perf-tools-next]$ perf check bpf,libtrafs
> 
>  Usage: perf check [<subcommand>] [<options>]
> 
>     -q, --quiet           do not show any warnings or messages
> 
> ⬢[acme@toolbox perf-tools-next]$
> 
> 
> I don't see a way to list what features can be tested against, would be
> great to have.
> 
> Also it just says that the usage is wrong, no indication as to why, I
> think this would be more informative:
> 
> 
> ⬢[acme@toolbox perf-tools-next]$ perf check bpf,libtrafs
> Unkown feature 'libtrafs', please use 'perf check feature --list' to see which ones are available.
> 
> ⬢[acme@toolbox perf-tools-next]$

Ah, to clarify, these comments are for the v12 series even being replies
to the v11 thread, I'll move to the v12 e-mail thread. Using b4 I got
the latest version, v12:

Cover: ./v12_20240628_adityag_introduce_perf_check_subcommand.cover
 Link: https://lore.kernel.org/r/20240628064236.1123851-1-adityag@linux.ibm.com
 Base: applies clean to current tree
       git checkout -b v12_20240628_adityag_linux_ibm_com HEAD
       git am ./v12_20240628_adityag_introduce_perf_check_subcommand.mbx
⬢[acme@toolbox perf-tools-next]$        git am ./v12_20240628_adityag_introduce_perf_check_subcommand.mbx
Applying: perf check: introduce check subcommand
Applying: perf version: update --build-options to use 'supported_features' array
Applying: perf tests task_analyzer: use perf check for libtraceevent support
Applying: tools/perf/tests: Update probe_vfs_getname.sh script to use perf check feature
⬢[acme@toolbox perf-tools-next]$