On Thu, Sep 14, 2023 at 11:58:51AM +0100, Harry van Haaren wrote:
> This commit changes the logic in the scheduler to always
> reset reorder-buffer (and QID/FID) entries when writing
> them. This avoids stale ROB/QID/FID data re-use, which
> previously caused ordering issues.
>
> Before this commit, release events left the history-list
> in an inconsistent state, and future events with op type of
> forward could be incorrectly reordered.
>
> Suggested-by: Bruce Richardson <bruce.richard...@intel.com>
> Signed-off-by: Harry van Haaren <harry.van.haa...@intel.com>
>
Acked-by: Bruce Richardson <bruce.richard...@intel.com>
Couple of very minor style comments below.
> ---
>
> v2:
> - Rework fix to simpler suggestion (Bruce)
> - Respin patchset to "apply order" (Bruce)
>
> ---
> drivers/event/sw/sw_evdev_scheduler.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/event/sw/sw_evdev_scheduler.c
> b/drivers/event/sw/sw_evdev_scheduler.c
> index de6ed21643..21c360770e 100644
> --- a/drivers/event/sw/sw_evdev_scheduler.c
> +++ b/drivers/event/sw/sw_evdev_scheduler.c
> @@ -90,8 +90,10 @@ sw_schedule_atomic_to_cq(struct sw_evdev *sw, struct
> sw_qid * const qid,
> sw->cq_ring_space[cq]--;
>
> int head = (p->hist_head++ & (SW_PORT_HIST_LIST-1));
> - p->hist_list[head].fid = flow_id;
> - p->hist_list[head].qid = qid_id;
> + p->hist_list[head] = (struct sw_hist_list_entry) {
> + .qid = qid_id,
> + .fid = flow_id,
> + };
>
> p->stats.tx_pkts++;
> qid->stats.tx_pkts++;
> @@ -162,8 +164,13 @@ sw_schedule_parallel_to_cq(struct sw_evdev *sw, struct
> sw_qid * const qid,
> qid->stats.tx_pkts++;
>
> const int head = (p->hist_head & (SW_PORT_HIST_LIST-1));
> - p->hist_list[head].fid = SW_HASH_FLOWID(qe->flow_id);
> - p->hist_list[head].qid = qid_id;
> + const uint32_t fid = SW_HASH_FLOWID(qe->flow_id);
> + p->hist_list[head] = (struct sw_hist_list_entry) {
> + .qid = qid_id,
> + .fid = fid,
> + };
> +
> +
You're adding some extra whitespace here. Can probably be fixed on apply.
And one final minor nit: if doing a new version, you can remove the
temporary variable for "fid". In my suggestion I only added it because I
had the assignment done on a single line and didn't want to wrap. Since
you've split the temporary struct across multiple lines, the temporary
variable isn't needed as the SW_HASH_FLOWID will fit on the assignment
line.
