From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by dpdk.org (Postfix) with ESMTP id F28DC3B5 for ; Mon, 6 Oct 2014 21:38:20 +0200 (CEST) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.14.9/8.14.5) with ESMTP id s96JjS8Q029307 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Mon, 6 Oct 2014 12:45:29 -0700 (PDT) Received: from ALA-MBB.corp.ad.wrs.com ([169.254.1.18]) by ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) with mapi id 14.03.0174.001; Mon, 6 Oct 2014 12:45:28 -0700 From: "Wiles, Roger Keith" To: "ANANYEV, KONSTANTIN" Thread-Topic: [dpdk-dev] [PATCH 2/2] Adding the routines rte_pktmbuf_alloc_bulk() and rte_pktmbuf_free_bulk() Thread-Index: AQHP4UOohbitp8XoLEu9K6u9lPldRZwjnJoAgAAAzQCAABEUAIAABTUAgAA7SIA= Date: Mon, 6 Oct 2014 19:45:27 +0000 Message-ID: <1AAECD5E-9A22-481D-9712-C75B8C1FAFC1@windriver.com> References: <1412464229-125521-1-git-send-email-keith.wiles@windriver.com> <1412464229-125521-2-git-send-email-keith.wiles@windriver.com> <59AF69C657FD0841A61C55336867B5B03441BE9E@IRSMSX103.ger.corp.intel.com> <5DD5FF6E-C045-4764-A5B1-877C88B023F5@windriver.com> <20141006145330.GA2548@BRICHA3-MOBL> <2601191342CEEE43887BDE71AB97725821390E75@IRSMSX105.ger.corp.intel.com> <545592DF-3306-49F7-8685-10BD021B9854@windriver.com> In-Reply-To: <545592DF-3306-49F7-8685-10BD021B9854@windriver.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: x-originating-ip: [172.25.40.166] MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH 2/2] Adding the routines rte_pktmbuf_alloc_bulk() and rte_pktmbuf_free_bulk() X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Oct 2014 19:38:21 -0000 On Oct 6, 2014, at 11:13 AM, Wiles, Roger Keith = wrote: > > On Oct 6, 2014, at 10:54 AM, Ananyev, Konstantin wrote: > >>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Bruce Richardson >>> Sent: Monday, October 06, 2014 3:54 PM >>> To: Wiles, Roger Keith (Wind River) >>> Cc: dev@dpdk.org >>> Subject: Re: [dpdk-dev] [PATCH 2/2] Adding the routines rte_pktmbuf_all= oc_bulk() and rte_pktmbuf_free_bulk() >>> >>> On Mon, Oct 06, 2014 at 03:50:38PM +0100, Wiles, Roger Keith wrote: >>>> Hi Bruce, >>>> >>>> Do I need to reject the for the new routines or just make sure the vec= tor driver does not get updated to use those routines? >>>> >>> >>> The new routines are probably useful in the general case. I see no issu= e >>> with having them in the code, so long as the vector driver is not modif= ied >>> to use them. >> >> I 'd say the same thing for non-vector RX/TX PMD code-paths too. >> >> BTW, are the new functions comments valid? >> >> + * @return >> + * - 0 if the number of mbufs allocated was ok >> + * - <0 is an ERROR. >> + */ >> +static inline int __rte_mbuf_raw_alloc_bulk( >> >> Though, as I can see __rte_mbuf_raw_alloc_bulk() returns either: >> - number of allocated mbuf (cnt) >> - negative error code > > Let me fix up the comments. >> >> And: >> + * @return >> + * - The number of valid mbufs pointers in the m_list array. >> + * - Zero if the request cnt could not be allocated. >> + */ >> +static inline int __attribute__((always_inline)) >> +rte_pktmbuf_alloc_bulk(struct rte_mempool *mp, struct rte_mbuf *m_list[= ], int16_t cnt) >> +{ >> + return __rte_mbuf_raw_alloc_bulk(mp, m_list, cnt); >> +} >> >> Shouldn't be "less than zero if the request cnt could not be allocated."= ? >> >> BTW, is there any point to have __rte_mbuf_raw_alloc_bulk() at all? >> After all, as you are calling rte_pktmbuf_reset() inside it, it doesn't = look __raw__ any more. >> Might be just put its content into rte_pktmbuf_alloc_bulk() and get rid = of it. >> > I was just following the non-bulk routine style __rte_mbuf_raw_alloc(), b= ut I can pull that into a single routine. > >> Also wonder, what is the advantage of having multiple counters inside th= e same loop? >> i.e: >> + for(i =3D 0; i < cnt; i++) { >> + m =3D *m_list++; >> >> Why not just: >> >> for(i =3D 0; i < cnt; i++) { >> m =3D &m_list[i]; >> >> Same for free: >> + while(npkts--) >> + rte_pktmbuf_free(*m_list++); >> >> While not just: >> for (i =3D 0; i < npkts; i++) >> rte_pktmbuf_free(&m_list[i]); > > Maybe I have it wrong or the compilers are doing the right thing now, but= at one point the &m_list[i] would cause the compiler to generate a shift o= r multiple of =91i=92 and then add it to the base of m_list. If that is not= the case anymore then I can update the code as you suggested. Using the *m= _list++ just adds the size of a pointer to a register and continues. I compared the clang assembler (.s file) output from an example test code I= wrote to see if we have any differences in the code using the two styles a= nd I found no difference and the code looked the same. I am not a Intel ass= embler expert and I would suggest someone else determine if it generates di= fferent code. I tried to compare the GCC outputs and it did look the same t= o me. I have attached the code and output, please let me know if I did something = wrong, but as it stands using the original style is what I want to go with. >> >> Konstantin >> >>> >>> /Bruce >>> >>>> Thanks >>>> ++Keith >>>> >>>> On Oct 6, 2014, at 3:56 AM, Richardson, Bruce wrote: >>>> >>>>> >>>>> >>>>>> -----Original Message----- >>>>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Keith Wiles >>>>>> Sent: Sunday, October 05, 2014 12:10 AM >>>>>> To: dev@dpdk.org >>>>>> Subject: [dpdk-dev] [PATCH 2/2] Adding the routines rte_pktmbuf_allo= c_bulk() >>>>>> and rte_pktmbuf_free_bulk() >>>>>> >>>>>> Minor helper routines to mirror the mempool routines and remove the = code >>>>>> from applications. The ixgbe_rxtx_vec.c routine could be changed to = use >>>>>> the ret_pktmbuf_alloc_bulk() routine inplace of rte_mempool_get_bulk= (). >>>>>> >>>>> >>>>> I believe such a change would cause a performance regression, as the = extra init code in the alloc_bulk() function would take >>> additional cycles and is not needed. The vector routines use the mempoo= l function directly, so that there is no overhead of mbuf >>> initialization, as the vector routines use their additional "knowledge"= of what the mbufs will be used for to init them in a faster manner >>> than can be done inside the mbuf library. >>>>> >>>>> /Bruce >>>>> >>>>>> Signed-off-by: Keith Wiles >>>>>> --- >>>>>> lib/librte_mbuf/rte_mbuf.h | 77 >>>>>> ++++++++++++++++++++++++++++++++++++++++++++++ >>>>>> 1 file changed, 77 insertions(+) >>>>>> >>>>>> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h >>>>>> index 1c6e115..f298621 100644 >>>>>> --- a/lib/librte_mbuf/rte_mbuf.h >>>>>> +++ b/lib/librte_mbuf/rte_mbuf.h >>>>>> @@ -546,6 +546,41 @@ static inline void rte_pktmbuf_reset(struct rte= _mbuf >>>>>> *m) >>>>>> } >>>>>> >>>>>> /** >>>>>> + * @internal Allocate a list of mbufs from mempool *mp*. >>>>>> + * The use of that function is reserved for RTE internal needs. >>>>>> + * Please use rte_pktmbuf_alloc_bulk(). >>>>>> + * >>>>>> + * @param mp >>>>>> + * The mempool from which mbuf is allocated. >>>>>> + * @param m_list >>>>>> + * The array to place the allocated rte_mbufs pointers. >>>>>> + * @param cnt >>>>>> + * The number of mbufs to allocate >>>>>> + * @return >>>>>> + * - 0 if the number of mbufs allocated was ok >>>>>> + * - <0 is an ERROR. >>>>>> + */ >>>>>> +static inline int __rte_mbuf_raw_alloc_bulk(struct rte_mempool *mp,= struct >>>>>> rte_mbuf *m_list[], int cnt) >>>>>> +{ >>>>>> + struct rte_mbuf *m; >>>>>> + int ret; >>>>>> + >>>>>> + ret =3D rte_mempool_get_bulk(mp, (void **)m_list, cnt); >>>>>> + if ( ret =3D=3D 0 ) { >>>>>> + int i; >>>>>> + for(i =3D 0; i < cnt; i++) { >>>>>> + m =3D *m_list++; >>>>>> +#ifdef RTE_MBUF_REFCNT >>>>>> + rte_mbuf_refcnt_set(m, 1); >>>>>> +#endif /* RTE_MBUF_REFCNT */ >>>>>> + rte_pktmbuf_reset(m); >>>>>> + } >>>>>> + ret =3D cnt; >>>>>> + } >>>>>> + return ret; >>>>>> +} >>>>>> + >>>>>> +/** >>>>>> * Allocate a new mbuf from a mempool. >>>>>> * >>>>>> * This new mbuf contains one segment, which has a length of 0. The p= ointer >>>>>> @@ -671,6 +706,32 @@ __rte_pktmbuf_prefree_seg(struct rte_mbuf *m) >>>>>> } >>>>>> >>>>>> /** >>>>>> + * Allocate a list of mbufs from a mempool into a mbufs array. >>>>>> + * >>>>>> + * This mbuf list contains one segment per mbuf, which has a length= of 0. The >>>>>> pointer >>>>>> + * to data is initialized to have some bytes of headroom in the buf= fer >>>>>> + * (if buffer size allows). >>>>>> + * >>>>>> + * The routine is just a simple wrapper routine to reduce code in t= he application >>>>>> and >>>>>> + * provide a cleaner API for multiple mbuf requests. >>>>>> + * >>>>>> + * @param mp >>>>>> + * The mempool from which the mbuf is allocated. >>>>>> + * @param m_list >>>>>> + * An array of mbuf pointers, cnt must be less then or equal to t= he size of the >>>>>> list. >>>>>> + * @param cnt >>>>>> + * Number of slots in the m_list array to fill. >>>>>> + * @return >>>>>> + * - The number of valid mbufs pointers in the m_list array. >>>>>> + * - Zero if the request cnt could not be allocated. >>>>>> + */ >>>>>> +static inline int __attribute__((always_inline)) >>>>>> +rte_pktmbuf_alloc_bulk(struct rte_mempool *mp, struct rte_mbuf *m_l= ist[], >>>>>> int16_t cnt) >>>>>> +{ >>>>>> + return __rte_mbuf_raw_alloc_bulk(mp, m_list, cnt); >>>>>> +} >>>>>> + >>>>>> +/** >>>>>> * Free a segment of a packet mbuf into its original mempool. >>>>>> * >>>>>> * Free an mbuf, without parsing other segments in case of chained >>>>>> @@ -708,6 +769,22 @@ static inline void rte_pktmbuf_free(struct rte_= mbuf >>>>>> *m) >>>>>> } >>>>>> } >>>>>> >>>>>> +/** >>>>>> + * Free a list of packet mbufs back into its original mempool. >>>>>> + * >>>>>> + * Free a list of mbufs by calling rte_pktmbuf_free() in a loop as = a wrapper >>>>>> function. >>>>>> + * >>>>>> + * @param m_list >>>>>> + * An array of rte_mbuf pointers to be freed. >>>>>> + * @param npkts >>>>>> + * Number of packets to free in list. >>>>>> + */ >>>>>> +static inline void rte_pktmbuf_free_bulk(struct rte_mbuf *m_list[],= int16_t >>>>>> npkts) >>>>>> +{ >>>>>> + while(npkts--) >>>>>> + rte_pktmbuf_free(*m_list++); >>>>>> +} >>>>>> + >>>>>> #ifdef RTE_MBUF_REFCNT >>>>>> >>>>>> /** >>>>>> -- >>>>>> 2.1.0 >>>>> >>>> >>>> Keith Wiles, Principal Technologist with CTO office, Wind River mobile= 972-213-5533 > > Keith Wiles, Principal Technologist with CTO office, Wind River mobile 97= 2-213-5533 Keith Wiles, Principal Technologist with CTO office, Wind River mobile 972-= 213-5533