From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavan Nikhilesh Bhagavatula Subject: Re: [PATCH] eal: added new `rte_lcore_is_service_lcore` API. Date: Fri, 15 Sep 2017 20:29:34 +0530 Message-ID: <20170915145933.GA16776@PBHAGAVATULA-LT> References: <1503501027-11046-1-git-send-email-pbhagavatula@caviumnetworks.com> <20170828150946.GA18980@PBHAGAVATULA-LT> <7169652.mOItyNrJXL@xps> <20170915144154.GA15346@PBHAGAVATULA-LT> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: thomas@monjalon.net, dev@dpdk.org To: "Van Haaren, Harry" Return-path: Received: from NAM01-BY2-obe.outbound.protection.outlook.com (mail-by2nam01on0045.outbound.protection.outlook.com [104.47.34.45]) by dpdk.org (Postfix) with ESMTP id 278142FDD for ; Fri, 15 Sep 2017 17:00:10 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, Sep 15, 2017 at 02:44:57PM +0000, Van Haaren, Harry wrote: > > > > -----Original Message----- > > From: Pavan Nikhilesh Bhagavatula [mailto:pbhagavatula@caviumnetworks.com] > > Sent: Friday, September 15, 2017 3:42 PM > > To: Van Haaren, Harry > > Cc: thomas@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:thomas@monjalon.net] > > > > Sent: Friday, September 15, 2017 2:53 PM > > > > To: Pavan Nikhilesh Bhagavatula ; Van > > Haaren, > > > > Harry > > > > 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:pbhagavatula@caviumnetworks.com] > > > > > > > On Mon, Aug 28, 2017 at 10:59:51AM +0000, Van Haaren, Harry wrote: > > > > > > > > From: Pavan Nikhilesh [mailto:pbhagavatula@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 > Agreed, will spin up a v2. Thanks, Pavan > > >