20/10/2020 10:34, Bruce Richardson: > On Mon, Oct 19, 2020 at 11:04:54PM +0200, Thomas Monjalon wrote: > > 19/10/2020 12:21, Bruce Richardson: > > > On Fri, Oct 16, 2020 at 06:46:12PM +0200, David Marchand wrote: > > > > On Fri, Oct 16, 2020 at 5:56 PM Bruce Richardson > > > > <bruce.richard...@intel.com> wrote: > > > > > > librte_eal.so is indeed built with the 64 value: > > > > > > $ pahole -C rte_mem_config build/install/lib64/librte_eal.so |grep > > > > > > memsegs > > > > > > die__process_function: tag not supported (INVALID)! > > > > > > struct rte_memseg_list memsegs[64]; /* 136 8704 > > > > > > */ > > > > > > > > > > > > > > > > > > But no trace of the custom value for external applications: > > > > > > $ grep -r RTE_MAX_MEMSEG_LISTS build/install > > > > > > build/install/include/rte_config.h:#ifndef RTE_MAX_MEMSEG_LISTS > > > > > > build/install/include/rte_config.h:#define RTE_MAX_MEMSEG_LISTS 128 > > > > > > Binary file build/install/lib64/librte_eal.a matches > > > > > > Binary file build/install/lib64/librte_eal.so.21.0 matches > > > > > > > > > > > > I can see the same using the meson option -Dc_args. > > > > > > > > > > Good point, I had not thought of external apps using these values. > > > > > > > > > > They are mostly for internal use, so maybe its worthwhile looking to > > > > > not > > > > > have them in a public header file. What do you think? Is it likely > > > > > that > > > > > apps would be using some of these values, or needs to know the > > > > > specifics? > > > > > > > > Some are publicly exposed, like RTE_MEMPOOL_CACHE_MAX_SIZE, > > > > RTE_PKTMBUF_HEADROOM, RTE_ETHDEV_RXTX_CALLBACKS, > > > > For those, either we propagate the overriden value to the installed > > > > rte_config.h or we refuse customisation. > > > > > > > I'd suggest the first 2 of those should possibly be global meson options. > > > > How the application is reading the meson options? > > > The meson options are reflected in the rte_build_config.h file. It's not > automatic, but they should be set there by the config/meson.build file. If > some are missed, they can be added, but I disagree that all meson options > should always be passed through to apps. It makes them part of the API, > perhaps unnecessarily, and therefore harder to change or adjust. > Furthermore why should an app ever need to care if a DPDK build included > the docs, or the kmods? > > > > Third should probably not be exposed at all. > > > > I think everything should be exposed. > > The application may need to know whether a feature is enabled or not, > > and what is a specific tuning value. > > > > I suspect it is the last blocker for meson adoption. Now that we removed > > the makefiles, we need to fill this gap urgently. > > > I really don't see this as a gap. With "make" we struggled with massive > amounts of build config, and we tried to remove as much as we can. While > this is reporting what's there rather than tweaking it, surely many of > these settings are just better as #defines in the individual header files - > if they need to be exposed at all.
I agree with the goal of moving these #defines internally. I just feel having wrong values in rte_config.h looks to be a bug.
