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

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

[Bruce Richardson]

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(+)

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
-- 
2.9.3

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

[Van Haaren, Harry]

> 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>

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

[Thomas Monjalon]

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