On Fri, Jan 19, 2024 at 08:58:17AM -0800, Rahul Gupta wrote: > From: Rahul Gupta <rahulg...@microsoft.com> > > In continuation to the following email, I am sending this patch. > (https://inbox.dpdk.org/dev/20231110172523.ga17...@microsoft.com/) > > Initialization 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 up to 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 applications > 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_eal_init_async(). > > Existing applications requires to just call- > rte_eal_init_wait_async_complete() after rte_eal_init() unless they wish > to leverage the optimization. > This part here is a bit problematic. For something as ubiquitous as rte_eal_init(), we should not be requiring existing application change. Instead, can you create a new init function to replace rte_eal_init() in the async case - and then eal_init can call that and then the async_complete function, to avoid duplicating code.
The goal should be to have existing apps unaffected, but to allow a path to faster startup for those that need it. In the original email you linked to above, we had such a proposal: rte_eal_init_async() & rte_eal_init_async_done(). Thanks, /Bruce
