Messages in this thread |  | | Subject | Re: [PATCH 13/18] rpmsg: glink: Add rx done command | From | Arun Kumar Neelakantam <> | Date | Wed, 23 Aug 2017 10:14:44 +0530 |
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On 8/22/2017 7:46 PM, Sricharan R wrote: > Hi, >>> + /* Take it off the tree of receive intents */ >>> + if (!intent->reuse) { >>> + spin_lock(&channel->intent_lock); >>> + idr_remove(&channel->liids, intent->id); >>> + spin_unlock(&channel->intent_lock); >>> + } >>> + >>> + /* Schedule the sending of a rx_done indication */ >>> + spin_lock(&channel->intent_lock); >>> + list_add_tail(&intent->node, &channel->done_intents); >>> + spin_unlock(&channel->intent_lock); >>> + >>> + schedule_work(&channel->intent_work); >> Adding one more parallel path will hit performance, if this worker could not get CPU cycles >> or blocked by other RT or HIGH_PRIO worker on global worker pool. > The idea is, by design to have parallel non-blocking paths for rx and tx (that is done as a > part of rx by sending the rx_done command), otherwise trying to send the rx_done > command in the rx isr context is a problem since the tx can wait for the FIFO space and > in worst case, can even lead to a potential deadlock if both the local and remote try > the same. Having said that, instead of queuing this work in to the global queue, this > can be put in to a local glink edge owned queue (or) a threaded isr ?, downstream does the > rx_done in a client specific worker.
Yes, mixing RX and TX path will cause dead lock. I am okay to use specific queue with HIGH_PRIO or a threaded isr. down stream uses both client specific worker and client RX cb [this mix the TX and RX path] which want to avoid. > > Regards, > Sricharan >
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