Re: [RFC] eal: RFC to refactor rte_eal_init into sub-functions

[rahul gupta <rahulrgupta27@gmail.com>]

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Hi Stephen,

Thanks for your review.
If I make it __rte_internal then, testpmd or our application can't use it.
So instead I am planning to make it __rte_experimental.

Regards,
Rahul.

On Fri, 3 Nov 2023 at 00:08, Stephen Hemminger <stephen@networkplumber.org>
wrote:

> On Thu,  2 Nov 2023 11:19:24 -0700
> Rahul Gupta <rahulgupt@linux.microsoft.com> wrote:
>
> > From: Rahul Gupta <rahulgupt@linux.microsoft.com>
> > To: dev@dpdk.org,  thomas@monjalon.net
> > Cc: sovaradh@linux.microsoft.com, okaya@kernel.org,
> sujithsankar@microsoft.com,  sowmini.varadhan@microsoft.com,
> rahulrgupta27@gmail.com,  Rahul Gupta <rahulgupt@microsoft.com>,  Rahul
> Gupta <rahulgupt@linux.microsoft.com>
> > Subject: [RFC] eal: RFC to refactor rte_eal_init into sub-functions
> > Date: Thu,  2 Nov 2023 11:19:24 -0700
> > X-Mailer: git-send-email 1.8.3.1
> >
> > From: Rahul Gupta <rahulgupt@microsoft.com>
> >
> > Initialization often requires rte_eal_init + rte_pktmbuf_pool_create
> > which can consume a total time of 500-600 ms:
> > a) For many devices FLR may take a significant chunk of time
> >    (200-250 ms in our use-case), this FLR is triggered during device
> >    probe in rte_eal_init().
> > b) rte_pktmbuf_pool_create() can consume upto 300-350 ms for
> > applications that require huge memory.
> >
> > This cost is incurred on each restart (which happens in our use-case
> > during binary updates for servicing).
> > This patch provides an optimization using pthreads that appplications
> > can use and which can save 200-230ms.
> >
> > In this patch, rte_eal_init() is refactored into two parts-
> > a) 1st part is dependent code ie- it’s a perquisite of the FLR and
> >    mempool creation. So this code needs to be executed before any
> >    pthreads. Its named as rte_eal_init_setup()
> > b) 2nd part of code is independent code ie- it can execute in parallel
> >    to mempool creation in a pthread. Its named as rte_probe_and_ioctl().
> >
> > Existing applications require no changes unless they wish to leverage
> > the optimization.
> >
> > If the application wants to use pthread functionality, it should call-
> > a) rte_eal_init_setup() then create two or more pthreads-
> > b) in one pthread call- rte_probe_and_ioctl(),
> > c) second pthread call- rte_pktmbuf_pool_create()
> > d) (optional) Other pthreads for  any other independent function.
> >
> > Signed-off-by: Rahul Gupta <rahulgupt@linux.microsoft.com>
>
> These probably marked internal rather than part of API/ABI.
>

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