[dpdk-dev] [PATCH] metrics: make number of metrics names configurable

[Bruce Richardson]

On Tue, Jul 28, 2020 at 12:59:22PM -0700, Stephen Hemminger wrote:
> On Tue, 28 Jul 2020 11:24:58 +0100
> Bruce Richardson <bruce.richardson at intel.com> wrote:
> 
> > On Thu, Jul 02, 2020 at 10:28:52AM -0700, Stephen Hemminger wrote:
> > > The maximum number of metrics is hardcoded at 256.
> > > This severely limits the usefulness of the library.
> > > It should be configurable like other limits in DPDK.
> > > 
> > > Fixes: 349950ddb9c5 ("metrics: add information metrics library")
> > > Cc: remy.horton at intel.com
> > > Cc: ciara.power at intel.com
> > > Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> > > ---
> > >  config/common_base               | 1 +
> > >  config/meson.build               | 2 +-
> > >  lib/librte_metrics/rte_metrics.h | 1 -
> > >  3 files changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/config/common_base b/config/common_base
> > > index fe30c515e5a3..f0212faec80c 100644
> > > --- a/config/common_base
> > > +++ b/config/common_base
> > > @@ -917,6 +917,7 @@ CONFIG_RTE_LIBRTE_JOBSTATS=y
> > >  # Compile the device metrics library
> > >  #
> > >  CONFIG_RTE_LIBRTE_METRICS=y
> > > +CONFIG_RTE_METRICS_MAX_METRICS=256
> > >  
> > >  #
> > >  # Compile the bitrate statistics library
> > > diff --git a/config/meson.build b/config/meson.build
> > > index 351e268c1f5b..cc8cb8fbf2f0 100644
> > > --- a/config/meson.build
> > > +++ b/config/meson.build
> > > @@ -238,7 +238,7 @@ dpdk_conf.set('RTE_ENABLE_TRACE_FP', get_option('enable_trace_fp'))
> > >  dpdk_conf.set('RTE_MAX_VFIO_GROUPS', 64)
> > >  dpdk_conf.set('RTE_DRIVER_MEMPOOL_BUCKET_SIZE_KB', 64)
> > >  dpdk_conf.set('RTE_LIBRTE_DPAA2_USE_PHYS_IOVA', true)
> > > -
> > > +dpdk_conf.set('RTE_METRICS_MAX_METRICS', 256)
> > >    
> > 
> > The meson.build file should really just be used for computed values, I
> > think. For build-time constants like this it's probably better put in
> > config/rte_config.h file.
> 
> config/rte_config.h is generated isn't it?
> 

For make builds it is, for meson there is a static rte_config.h which
includes the dynamically-generated rte_build_config.h.

While nothing mandates this design, and we can change it if people find it
confusing, I though it worthwhile to have a config header file for stuff
like this that is not normally configurable, but some folks might want to
tweak in custom builds. For 20.11 I'll try and remember to update the docs
to cover it a bit, so that people are more aware its there.

/Bruce