From: Morten Brørup <mb@smartsharesystems.com> To: "Honnappa Nagarahalli" <Honnappa.Nagarahalli@arm.com>, "Ananyev, Konstantin" <konstantin.ananyev@intel.com>, "Dharmik Thakkar" <Dharmik.Thakkar@arm.com>, "Olivier Matz" <olivier.matz@6wind.com>, "Andrew Rybchenko" <andrew.rybchenko@oktetlabs.ru> Cc: <dev@dpdk.org>, "nd" <nd@arm.com>, "Ruifeng Wang" <Ruifeng.Wang@arm.com>, "nd" <nd@arm.com>, "nd" <nd@arm.com> Subject: Re: [dpdk-dev] [RFC] mempool: implement index-based per core cache Date: Sun, 31 Oct 2021 09:14:06 +0100 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D86C83@smartserver.smartshare.dk> (raw) In-Reply-To: <DBAPR08MB5814FAB214D809E9E82DB9EF98AE9@DBAPR08MB5814.eurprd08.prod.outlook.com> > From: Morten Brørup > Sent: Saturday, 30 October 2021 12.24 > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Honnappa > > Nagarahalli > > Sent: Monday, 4 October 2021 18.36 > > > > <snip> > > > > > > > > > > > > Current mempool per core cache implementation is based on > > pointer > > > > > > For most architectures, each pointer consumes 64b Replace it > > with > > > > > > index-based implementation, where in each buffer is addressed > > by > > > > > > (pool address + index) > > I like Dharmik's suggestion very much. CPU cache is a critical and > limited resource. > > DPDK has a tendency of using pointers where indexes could be used > instead. I suppose pointers provide the additional flexibility of > mixing entries from different memory pools, e.g. multiple mbuf pools. > > > > > > > > > > > I don't think it is going to work: > > > > > On 64-bit systems difference between pool address and it's elem > > > > > address could be bigger than 4GB. > > > > Are you talking about a case where the memory pool size is more > > than 4GB? > > > > > > That is one possible scenario. > > That could be solved by making the index an element index instead of a > pointer offset: address = (pool address + index * element size). Or instead of scaling the index with the element size, which is only known at runtime, the index could be more efficiently scaled by a compile time constant such as RTE_MEMPOOL_ALIGN (= RTE_CACHE_LINE_SIZE). With a cache line size of 64 byte, that would allow indexing into mempools up to 256 GB in size. > > > > Another possibility - user populates mempool himself with some > > external > > > memory by calling rte_mempool_populate_iova() directly. > > Is the concern that IOVA might not be contiguous for all the memory > > used by the mempool? > > > > > I suppose such situation can even occur even with normal > > > rte_mempool_create(), though it should be a really rare one. > > All in all, this feature needs to be configurable during compile > time.
next prev parent reply other threads:[~2021-10-31 8:14 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-30 17:27 Dharmik Thakkar 2021-10-01 12:36 ` Jerin Jacob 2021-10-01 15:44 ` Honnappa Nagarahalli 2021-10-01 17:32 ` Jerin Jacob 2021-10-01 17:57 ` Honnappa Nagarahalli 2021-10-01 18:21 ` Jerin Jacob 2021-10-01 21:30 ` Ananyev, Konstantin 2021-10-02 0:07 ` Honnappa Nagarahalli 2021-10-02 18:51 ` Ananyev, Konstantin 2021-10-04 16:36 ` Honnappa Nagarahalli 2021-10-30 10:23 ` Morten Brørup 2021-10-31 8:14 ` Morten Brørup [this message] 2021-11-03 15:12 ` Dharmik Thakkar 2021-11-03 15:52 ` Morten Brørup 2021-11-04 4:42 ` Dharmik Thakkar 2021-11-04 8:04 ` Morten Brørup 2021-11-08 4:32 ` Honnappa Nagarahalli 2021-11-08 7:22 ` Morten Brørup 2021-11-08 15:29 ` Honnappa Nagarahalli 2021-11-08 15:39 ` Morten Brørup 2021-11-08 15:46 ` Honnappa Nagarahalli 2021-11-08 16:03 ` Morten Brørup 2021-11-08 16:47 ` Jerin Jacob 2021-12-24 22:59 ` [PATCH 0/1] " Dharmik Thakkar 2021-12-24 22:59 ` [PATCH 1/1] " Dharmik Thakkar 2022-01-11 2:26 ` Ananyev, Konstantin 2022-01-13 5:17 ` Dharmik Thakkar 2022-01-13 10:37 ` Ananyev, Konstantin 2022-01-19 15:32 ` Dharmik Thakkar 2022-01-21 11:25 ` Ananyev, Konstantin 2022-01-21 11:31 ` Ananyev, Konstantin 2022-03-24 19:51 ` Dharmik Thakkar 2021-12-25 0:16 ` [PATCH 0/1] " Morten Brørup 2022-01-07 11:15 ` Bruce Richardson 2022-01-07 11:29 ` Morten Brørup 2022-01-07 13:50 ` Bruce Richardson 2022-01-08 9:37 ` Morten Brørup 2022-01-10 6:38 ` Jerin Jacob 2022-01-13 5:31 ` Dharmik Thakkar 2022-01-13 5:36 ` [PATCH v2 " Dharmik Thakkar 2022-01-13 5:36 ` [PATCH v2 1/1] " Dharmik Thakkar 2022-01-13 10:18 ` Jerin Jacob 2022-01-20 8:21 ` Morten Brørup 2022-01-21 6:01 ` Honnappa Nagarahalli 2022-01-21 7:36 ` Morten Brørup 2022-01-24 13:05 ` Ray Kinsella 2022-01-21 9:12 ` Bruce Richardson 2022-01-23 7:13 ` Wang, Haiyue
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