[dpdk-dev] event/sw: fix events mis-identified as needing reorder

Message ID 20170414151815.12850-1-bruce.richardson@intel.com (mailing list archive)
State Accepted, archived
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Bruce Richardson April 14, 2017, 3:18 p.m. UTC
  When taking events from a port, we checked the history list to check if the
event needed to be put back in order i.e. originally came from a reordered
queue type. The check for reordering involved checking if the reorder
buffer entry pointer was null. However, after that pointer was used it was
never cleared to null again.

This caused problems when we had mixed reordered and atomic or parallel
events, as the events from the latter two queue types were misidentified as
needing reordering. This let in some cases to crashes, but mostly led to
dropping events, and then application lock-up.

Fixes: 617995dfc5b2 ("event/sw: add scheduling logic")

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/event/sw/sw_evdev_scheduler.c | 1 +
 1 file changed, 1 insertion(+)
  

Comments

Van Haaren, Harry April 14, 2017, 3:28 p.m. UTC | #1
> From: Richardson, Bruce
> Sent: Friday, April 14, 2017 4:18 PM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>
> Cc: dev@dpdk.org; Richardson, Bruce <bruce.richardson@intel.com>
> Subject: [PATCH] event/sw: fix events mis-identified as needing reorder
> 
> When taking events from a port, we checked the history list to check if the
> event needed to be put back in order i.e. originally came from a reordered
> queue type. The check for reordering involved checking if the reorder
> buffer entry pointer was null. However, after that pointer was used it was
> never cleared to null again.
> 
> This caused problems when we had mixed reordered and atomic or parallel
> events, as the events from the latter two queue types were misidentified as
> needing reordering. This let in some cases to crashes, but mostly led to
> dropping events, and then application lock-up.
> 
> Fixes: 617995dfc5b2 ("event/sw: add scheduling logic")
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

+CC Thomas, would you pick this directly to master please, as no next-eventdev will be merged, thanks.

Acked-by: Harry van Haaren <harry.van.haaren@intel.com>
  
Thomas Monjalon April 19, 2017, 10:31 p.m. UTC | #2
14/04/2017 17:28, Van Haaren, Harry:
> From: Richardson, Bruce
> Sent: Friday, April 14, 2017 4:18 PM
> > 
> > When taking events from a port, we checked the history list to check if
> > the
> > event needed to be put back in order i.e. originally came from a reordered
> > queue type. The check for reordering involved checking if the reorder
> > buffer entry pointer was null. However, after that pointer was used it was
> > never cleared to null again.
> > 
> > This caused problems when we had mixed reordered and atomic or parallel
> > events, as the events from the latter two queue types were misidentified
> > as
> > needing reordering. This let in some cases to crashes, but mostly led to
> > dropping events, and then application lock-up.
> > 
> > Fixes: 617995dfc5b2 ("event/sw: add scheduling logic")
> > 
> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> +CC Thomas, would you pick this directly to master please, as no
> next-eventdev will be merged, thanks.
> 
> Acked-by: Harry van Haaren <harry.van.haaren@intel.com>

Applied, thanks
  

Patch

diff --git a/drivers/event/sw/sw_evdev_scheduler.c b/drivers/event/sw/sw_evdev_scheduler.c
index e008b51..a333a6f 100644
--- a/drivers/event/sw/sw_evdev_scheduler.c
+++ b/drivers/event/sw/sw_evdev_scheduler.c
@@ -448,6 +448,7 @@  __pull_port_lb(struct sw_evdev *sw, uint32_t port_id, int allow_reorder)
 				struct reorder_buffer_entry *rob_entry =
 						hist_entry->rob_entry;
 
+				hist_entry->rob_entry = NULL;
 				/* Although fragmentation not currently
 				 * supported by eventdev API, we support it
 				 * here. Open: How do we alert the user that