Re: [PATCH V2 net 2/3] net: hibmcge: fix the division by zero issue

[Jijie Shao <shaojijie@huawei.com>]

on 2025/8/6 9:14, Jakub Kicinski wrote:
> On Sat, 2 Aug 2025 20:32:25 +0800 Jijie Shao wrote:
>>   static inline u32 hbg_get_queue_used_num(struct hbg_ring *ring)
>>   {
>> +	if (!ring->len)
>> +		return 0;
>> +
>>   	return (ring->ntu + ring->len - ring->ntc) % ring->len;
> This should probably be a READ_ONCE() to a temporary variable.
> There is no locking in debugfs, AFAICT, the value may change
> between the test and the division / modulo.

Yes, there is indeed a very short time window.
I will add READ_ONCE() to ring->len and read it only once.

Thanks
Jijie Shao