On Tue, Sep 10, 2019 at 02:40:20PM +0800, Liuyixian (Eason) wrote: > > > On 2019/9/8 16:03, Leon Romanovsky wrote: > > On Thu, Sep 05, 2019 at 08:31:11PM +0800, Weihang Li wrote: > >> From: Yixian Liu <liuyixian@xxxxxxxxxx> > >> > >> Hip08 has the feature flush cqe, which help to flush wqe in workqueue > >> (sq and rq) when error happened by transmitting producer index with > >> mailbox to hardware. Flush cqe is emplemented in post send and recv > >> verbs. However, under NVMe cases, these verbs will be called under > >> softirq context, and it will lead to following calltrace with > >> current driver as mailbox used by flush cqe can go to sleep. > >> > >> This patch solves this problem by using workqueue to do flush cqe, > > > > Unbelievable, almost every bug in this driver is solved by introducing > > workqueue. You should fix "sleep in flush path" issue and not by adding > > new workqueue. > > > Hi Leon, > > Thanks for the comment. > Up to now, for hip08, only one place use workqueue in hns_roce_hw_v2.c > where for irq prints. Thanks to our lack of desire to add more workqueues and previous patches which removed extra workqueues from the driver. > > The solution for flush cqe in this patch is as follow: > While flush cqe should be implement, the driver should modify qp to error state > through mailbox with the newest product index of sq and rq, the hardware then > can flush all outstanding wqes in sq and rq. > > That's the whole mechanism of flush cqe, also is the flush path. We can't > change neither mailbox sleep attribute or flush cqe occurred in post send/recv. > To avoid the calltrace of flush cqe in post verbs under NVMe softirq, > use workqueue for flush cqe seems reasonable. > > As far as I know, there is no other alternative solution for this situation. > I will be very grateful if you reminder me more information. ib_drain_rq/ib_drain_sq/ib_drain_qp???? > > Thanks > > > _______________________________________________ > > Linuxarm mailing list > > Linuxarm@xxxxxxxxxx > > http://hulk.huawei.com/mailman/listinfo/linuxarm > > > > >
