Re: [dpdk-dev] [PATCH] eal/ipc: stop async IPC loop on callback request

[Tan, Jianfeng]

On 4/10/2018 6:03 PM, Anatoly Burakov wrote:
EAL did not stop processing further asynchronous requests on
encountering a request that should trigger the callback. This
resulted in erasing valid requests but not triggering them.

That means one wakeup could process multiple replies, and following 
process_async_request() will erase some valid requests?


Fix this by stopping the loop once we have a request that we
can trigger. Also, remove unnecessary check for trigger
request being NULL.

Fixes: f05e26051c15 ("eal: add IPC asynchronous request")
Cc: anatoly.bura...@intel.com

Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>


---
  lib/librte_eal/common/eal_common_proc.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_proc.c 
b/lib/librte_eal/common/eal_common_proc.c
index f98622f..1ea3b58 100644
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -510,11 +510,11 @@ async_reply_handle(void *arg __rte_unused)
                                        TAILQ_REMOVE(&pending_requests.requests,
                                                        sr, next);
                                        free(sr);
-                               } else if (action == ACTION_TRIGGER &&
-                                               trigger == NULL) {
+                               } else if (action == ACTION_TRIGGER) {
                                        TAILQ_REMOVE(&pending_requests.requests,
                                                        sr, next);
                                        trigger = sr;
+                                       break;

If I understand it correctly above, break here, we will trigger an async 
action, and then go back to sleep with some ready requests not handled? 
Seems that we shall unlock, process, and lock here. Right?

Thanks,
Jianfeng

                                }
                        }
                }