On Tue, Mar 17, 2020 at 12:05:10PM -0400, Dennis Dalessandro wrote:
> +static void flush_pq_iowait(struct hfi1_user_sdma_pkt_q *pq)
> +{
> + unsigned long flags;
> + seqlock_t *lock = pq->busy.lock;
> +
> + if (!lock)
> + return;
> + write_seqlock_irqsave(lock, flags);
> + if (!list_empty(&pq->busy.list)) {
> + list_del_init(&pq->busy.list);
> + pq->busy.lock = NULL;
> + }
> + write_sequnlock_irqrestore(lock, flags);
I'm trying to grasp how a seqlock is protecting a list_empty and
list_del_init, and this seems.. uh.. insane?
The only place that uses seqlock in infiniband is in hfi1
It only calls seqlock_init and write_seqlock
Never read_seqlock
So, this isn't a seqlock, it is a normal spinlock obfuscated as a
seqlock.
Please clean this mess too.
I don't know what to do with this patch, it might well be functionally
right, but everything about reading it screams wrong wrong wrong. I
don't want to send it to Linus in -rc like this.
At least add something to the commit message asking temporary
forgiveness for this madness.
Also s/insure/ensure/, right?
Jason
