From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: "Walker, Benjamin" <benjamin.walker@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: "thomas@monjalon.net" <thomas@monjalon.net>,
"andras.kovacs@ericsson.com" <andras.kovacs@ericsson.com>,
"Wiles, Keith" <keith.wiles@intel.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>
Subject: Re: [dpdk-dev] [RFC v2 00/23] Dynamic memory allocation for DPDK
Date: Fri, 22 Dec 2017 09:13:04 +0000 [thread overview]
Message-ID: <c1a8f9f5-390d-c9ea-958a-85c0bcac60b3@intel.com> (raw)
In-Reply-To: <1513892309.2658.80.camel@intel.com>
On 21-Dec-17 9:38 PM, Walker, Benjamin wrote:
> On Tue, 2017-12-19 at 11:14 +0000, Anatoly Burakov wrote:
>>
>
>> Quick outline of all changes done as part of this patchset:
>>
>> * Malloc heap adjusted to handle holes in address space
>> * Single memseg list replaced by multiple expandable memseg lists
>> * VA space for hugepages is preallocated in advance
>> * Added dynamic alloc/free for pages, happening as needed on malloc/free
>
> SPDK will need some way to register for a notification when pages are allocated
> or freed. For storage, the number of requests per second is (relative to
> networking) fairly small (hundreds of thousands per second in a traditional
> block storage stack, or a few million per second with SPDK). Given that, we can
> afford to do a dynamic lookup from va to pa/iova on each request in order to
> greatly simplify our APIs (users can just pass pointers around instead of
> mbufs). DPDK has a way to lookup the pa from a given va, but it does so by
> scanning /proc/self/pagemap and is very slow. SPDK instead handles this by
> implementing a lookup table of va to pa/iova which we populate by scanning
> through the DPDK memory segments at start up, so the lookup in our table is
> sufficiently fast for storage use cases. If the list of memory segments changes,
> we need to know about it in order to update our map.
Hi Benjamin,
So, in other words, we need callbacks on alloa/free. What information
would SPDK need when receiving this notification? Since we can't really
know in advance how many pages we allocate (it may be one, it may be a
thousand) and they no longer are guaranteed to be contiguous, would a
per-page callback be OK? Alternatively, we could have one callback per
operation, but only provide VA and size of allocated memory, while
leaving everything else to the user. I do add a virt2memseg() function
which would allow you to look up segment physical addresses easier, so
you won't have to manually scan memseg lists to get IOVA for a given VA.
Thanks for your feedback and suggestions!
>
> Having the map also enables a number of other nice things - for instance we
> allow users to register memory that wasn't allocated through DPDK and use it for
> DMA operations. We keep that va to pa/iova mapping in the same map. I appreciate
> you adding APIs to dynamically register this type of memory with the IOMMU on
> our behalf. That allows us to eliminate a nasty hack where we were looking up
> the vfio file descriptor through sysfs in order to send the registration ioctl.
>
>> * Added contiguous memory allocation API's for rte_malloc and rte_memzone
>> * Integrated Pawel Wodkowski's patch [1] for registering/unregistering memory
>> with VFIO
--
Thanks,
Anatoly
next prev parent reply other threads:[~2017-12-22 9:13 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-19 11:14 Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 01/23] eal: move get_virtual_area out of linuxapp eal_memory.c Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 02/23] eal: add function to report number of detected sockets Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 03/23] eal: add rte_fbarray Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 04/23] eal: move all locking to heap Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 05/23] eal: protect malloc heap stats with a lock Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 06/23] eal: make malloc a doubly-linked list Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 07/23] eal: make malloc_elem_join_adjacent_free public Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 08/23] eal: add "single file segments" command-line option Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 09/23] eal: add "legacy memory" option Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 10/23] eal: read hugepage counts from node-specific sysfs path Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 11/23] eal: replace memseg with memseg lists Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 12/23] eal: add support for dynamic memory allocation Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 13/23] eal: make use of dynamic memory allocation for init Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 14/23] eal: add support for dynamic unmapping of pages Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 15/23] eal: add API to check if memory is physically contiguous Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 16/23] eal: enable dynamic memory allocation/free on malloc/free Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 17/23] eal: add backend support for contiguous memory allocation Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 18/23] eal: add rte_malloc support for allocating contiguous memory Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 19/23] eal: enable reserving physically contiguous memzones Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 20/23] eal: make memzones use rte_fbarray Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 21/23] mempool: add support for the new memory allocation methods Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 22/23] vfio: allow to map other memory regions Anatoly Burakov
2017-12-19 11:14 ` [dpdk-dev] [RFC v2 23/23] eal: map/unmap memory with VFIO when alloc/free pages Anatoly Burakov
2017-12-19 15:46 ` [dpdk-dev] [RFC v2 00/23] Dynamic memory allocation for DPDK Stephen Hemminger
2017-12-19 16:02 ` Burakov, Anatoly
2017-12-19 16:06 ` Stephen Hemminger
2017-12-19 16:09 ` Burakov, Anatoly
2017-12-21 21:38 ` Walker, Benjamin
2017-12-22 9:13 ` Burakov, Anatoly [this message]
2017-12-26 17:19 ` Walker, Benjamin
2018-02-02 19:28 ` Yongseok Koh
2018-02-05 10:03 ` Burakov, Anatoly
2018-02-05 10:18 ` Nélio Laranjeiro
2018-02-05 10:36 ` Burakov, Anatoly
2018-02-06 9:10 ` Nélio Laranjeiro
2018-02-14 2:01 ` Yongseok Koh
2018-02-14 9:32 ` Burakov, Anatoly
2018-02-14 18:13 ` Yongseok Koh
2018-01-13 14:13 ` Burakov, Anatoly
2018-01-23 22:33 ` Yongseok Koh
2018-01-25 16:18 ` Burakov, Anatoly
2018-02-14 8:04 ` Thomas Monjalon
2018-02-14 10:07 ` Burakov, Anatoly
2018-04-25 16:02 ` Burakov, Anatoly
2018-04-25 16:12 ` Stephen Hemminger
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