> -----Original Message----- > From: Pavan Nikhilesh Bhagavatula [mailto:pbhagavat...@caviumnetworks.com] > Sent: Friday, September 15, 2017 3:42 PM > To: Van Haaren, Harry <harry.van.haa...@intel.com> > Cc: tho...@monjalon.net; dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH] eal: added new `rte_lcore_is_service_lcore` > API. > > On Fri, Sep 15, 2017 at 01:57:42PM +0000, Van Haaren, Harry wrote: > > > From: Thomas Monjalon [mailto:tho...@monjalon.net] > > > Sent: Friday, September 15, 2017 2:53 PM > > > To: Pavan Nikhilesh Bhagavatula <pbhagavat...@caviumnetworks.com>; Van > Haaren, > > > Harry <harry.van.haa...@intel.com> > > > Cc: dev@dpdk.org > > > Subject: Re: [dpdk-dev] [PATCH] eal: added new > > > `rte_lcore_is_service_lcore` > > > API. > > > > > > 28/08/2017 17:09, Pavan Nikhilesh Bhagavatula: > > > > On Mon, Aug 28, 2017 at 01:49:37PM +0000, Van Haaren, Harry wrote: > > > > > From: Pavan Nikhilesh Bhagavatula > [mailto:pbhagavat...@caviumnetworks.com] > > > > > > On Mon, Aug 28, 2017 at 10:59:51AM +0000, Van Haaren, Harry wrote: > > > > > > > From: Pavan Nikhilesh [mailto:pbhagavat...@caviumnetworks.com] > > > > > > > > --- a/lib/librte_eal/common/include/rte_lcore.h > > > > > > > > +++ b/lib/librte_eal/common/include/rte_lcore.h > > > > > > > > @@ -180,6 +180,24 @@ rte_lcore_is_enabled(unsigned lcore_id) > > > > > > > > } > > > > > > > > > > > > > > > > /** > > > > > > > > + * Test if an lcore is service lcore. > > > > > > > > + * > > > > > > > > + * @param lcore_id > > > > > > > > + * The identifier of the lcore, which MUST be between 0 and > > > > > > > > + * RTE_MAX_LCORE-1. > > > > > > > > + * @return > > > > > > > > + * True if the given lcore is service; false otherwise. > > > > > > > > + */ > > > > > > > > +static inline int > > > > > > > > +rte_lcore_is_service_lcore(unsigned lcore_id) > > > > > > > > +{ > > > > > > > > + struct rte_config *cfg = rte_eal_get_configuration(); > > > > > > > > + if (lcore_id >= RTE_MAX_LCORE) > > > > > > > > + return 0; > > > > > > > > + return cfg->lcore_role[lcore_id] == ROLE_SERVICE; > > > > > > > > +} > > > > > > > > > > > > > > No header file and Static inline - so this is only to be used > > > internally in the service > > > > > > cores library? > > > > > > > If so, the function should actually be used, instead of only added > but > > > not used in the > > > > > > library itself. > > > > > > > > > > > > > > > > > > > The enum rte_lcore_role_t has ROLE_SERVICE which tells that a > particular > > > lcore is > > > > > > a service lcore as well as an EAL thread some libraries such as > rte_timer > > > allow > > > > > > specific operations only over EAL threads. > > > > > > > > > > Understood that role of cores is important, and that rte_timer might > > > require this information. > > > > > > > > > > > > > > > > The rte_timer lib uses the rte_is_lcore_enabled() call to check if a > > > lcore is an > > > > > > EAL thread, Which checks if the lcore role is ROLE_RTE. But it > should > > > also > > > > > > allow timers to be registered on a service core as processing those > > > timers can > > > > > > be done on them. > > > > > > > > > > No problem from me here either - although it's the Timers library > > > maintainer that should check this. > > > > > > > > > > > > > > > > This new function allows such libraries to check if the role is > > > > > > ROLE_SERVICE and allow those operations. > > > > > > > > > > If the timers library requires information about service-cores, it > should > > > use a public API to retrieve that information. Having "internal" functions > > > between libraries is not nice. > > > > > > > > > > I think a better design would be to add this function as a public > function, > > > (add it to the .map files etc) and then call the public function from the > > > timers library. > > > > > > > > > > Does that sound like a good solution? -Harry > > > > > > > > > > > > > The file rte_lcore.h is in librte_eal/common/include I couldn't find a > .map > > > > file for eal/common and also other functions that are present in > rte_lcore.h > > > > aren't mapped in eal/linuxapp or eal/bsdapp. > > > > I think it is fine as the functions are static inline. > > > > > > We must avoid adding more inline functions without a good justification. > > > The inline functions are tolerated for performance reasons only. > > > > > > We could also choose to add this function to rte_service.h ? > > > > Yes that is an option, and OK with me. > > > > @Pavan what do you think of adding it to service.h, implement in .c and add > to .map? > > > > The ROLE_SERVICE/ROLE_RTE defines the role of a lcore so it made sense to put > it in rte_lcore.h as lcore properties are accessed mostly through this header. > I'm fine with adding it to service.h as suggested by Harry. > > -Pavan
*as suggested by Thomas ;) Initially I thought it made more sense in lcore.h too, however the application should only require knowing if core X is a service core if it cares about services / service-cores, hence I'm fine with rte_service.h too. -Harry
