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: Tue, 29 Aug 2017 19:14:55 +0530 Message-ID: <20170829134454.GA11730@PBHAGAVATULA-LT> References: <1503501027-11046-1-git-send-email-pbhagavatula@caviumnetworks.com> <20170828113302.GA22141@PBHAGAVATULA-LT> <20170828150946.GA18980@PBHAGAVATULA-LT> <20170828154259.GA20482@PBHAGAVATULA-LT> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org To: "Van Haaren, Harry" Return-path: Received: from NAM02-BL2-obe.outbound.protection.outlook.com (mail-bl2nam02on0085.outbound.protection.outlook.com [104.47.38.85]) by dpdk.org (Postfix) with ESMTP id ACF0411F5 for ; Tue, 29 Aug 2017 15:45:23 +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 Tue, Aug 29, 2017 at 01:17:18PM +0000, Van Haaren, Harry wrote: > > From: Pavan Nikhilesh Bhagavatula [mailto:pbhagavatula@caviumnetworks.com] > > Sent: Monday, August 28, 2017 4:43 PM > > To: Van Haaren, Harry > > Cc: dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH] eal: added new `rte_lcore_is_service_lcore` API. > > > > On Mon, Aug 28, 2017 at 03:24:06PM +0000, Van Haaren, Harry wrote: > > > > > > > > > > -----Original Message----- > > > > From: Pavan Nikhilesh Bhagavatula [mailto:pbhagavatula@caviumnetworks.com] > > > > Sent: Monday, August 28, 2017 4:10 PM > > > > To: Van Haaren, Harry > > > > Cc: dev@dpdk.org > > > > Subject: Re: [dpdk-dev] [PATCH] eal: added new `rte_lcore_is_service_lcore` API. > > > > > > > > On Mon, Aug 28, 2017 at 01:49:37PM +0000, Van Haaren, Harry wrote: > > > > > > From: Pavan Nikhilesh Bhagavatula [mailto:pbhagavatula@caviumnetworks.com] > > > > > > Sent: Monday, August 28, 2017 12:33 PM > > > > > > To: Van Haaren, Harry > > > > > > Cc: dev@dpdk.org > > > > > > Subject: Re: [dpdk-dev] [PATCH] eal: added new `rte_lcore_is_service_lcore` API. > > > > > > > > > > > > On Mon, Aug 28, 2017 at 10:59:51AM +0000, Van Haaren, Harry wrote: > > > > > > > > From: Pavan Nikhilesh [mailto:pbhagavatula@caviumnetworks.com] > > > > > > > > Sent: Wednesday, August 23, 2017 4:10 PM > > > > > > > > To: dev@dpdk.org > > > > > > > > Cc: Van Haaren, Harry ; Pavan Nikhilesh > > > > > > > > > > > > > > > > Subject: [dpdk-dev] [PATCH] eal: added new `rte_lcore_is_service_lcore` API. > > > > > > > > > > > > > > > > This API can be used to test if an lcore(EAL thread) is a service lcore. > > > > > > > > > > > > > > > > Signed-off-by: Pavan Nikhilesh > > > > > > > > --- > > > > > > > > lib/librte_eal/common/include/rte_lcore.h | 18 ++++++++++++++++++ > > > > > > > > 1 file changed, 18 insertions(+) > > > > > > > > > > > > > > > > diff --git a/lib/librte_eal/common/include/rte_lcore.h > > > > > > > > b/lib/librte_eal/common/include/rte_lcore.h > > > > > > > > index 50e0d0f..7854ea1 100644 > > > > > > > > --- 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. > > > > > > > > -Pavan > > > > > > OK - I was looking at this from a service core library POV. The intent seems to be to update > > EAL in order to allow detection of a core having a ROLE_SERVICE. Now I see your intent better, > > no problem with the approach. Correct that static-inline functions don't need .map file > > entries (cause they're inlined :) > > > > > > One technical issue: > > > > + if (lcore_id >= RTE_MAX_LCORE) > > > > + return 0; > > > > > > This should return a -ERROR value, as 0 is a valid return value that should indicate one > > thing (and one thing only) "not a service core". > > > > The function function follows the same structure as rte_lcore_is_enabled i.e. > > returns either true(1) or false(0). So, I think returning 0 would be fine?. If > > not I'll gladly send a v2. > > I looked that that function too - I'm not sure what's better API design... > Lets stay consistent with other functions in the file; so keep your current implementation. > > Note that these service core patches depend on the Service Cores rework patchset (currently > v2 available here: http://dpdk.org/dev/patchwork/patch/27684/ ) > > @Pavan, if you have time to Ack the patches this one is based on that would be fantastic. Sure Harry will go through the patch set. > > Acked-by: Harry van Haaren Thanks, Pavan.