Re: [PATCH] net: hinic: avoid kernel hung in hinic_get_stats64()

[maqiao]

在 2022/6/30 下午9:59, Eric Dumazet 写道:
> On Thu, Jun 30, 2022 at 3:57 PM maqiao <mqaio@xxxxxxxxxxxxxxxxx> wrote:
> > 在 2022/6/30 下午6:23, Eric Dumazet 写道:
>
> > > Note: The following is racy, because multiple threads can call
> > > hinic_get_stats64() at the same time.
> > > It needs a loop, see include/linux/u64_stats_sync.h for detail.
> > Thanks for reminding, and I noticed that nic_tx_stats/nic_rx_stats has
> > been protected by u64_stats_sync in update_t/rx_stats(), it seems that
> > it's unnecessary to use spinlock in update_nic_stats().
>
> It is necessary to use the spinlock to protect writers among themselves.
Ohhh, sorry, I was wrong.
I did not realize that seqlock cannot prevent mutil writers enter 
critical section...
> > I will send v2 as soon as possible, thanks.