Re: An interesting anomaly in NFS client...

On 07/11/2024 02:43, George Neville-Neil wrote:
> Howdy,
> 
> We've been digging into an interesting possible issue in the FreeBSD NFS client. 
> Here is the scenario. I have a FreeBSD VM on my Mac, the Mac is the NFS server, 
> the VM is the client. I then attempt to build an out of tree kernel module that 
> I'm working on. The build looks like it's hanging for 1.5 seconds, and when we 
> look at the packets (pcap file attached) we see a ton of GETATTRs over the first 
> 1.5 seconds. I've put the pcap up here: oct_8_2024.pcapng <https:// 
> people.freebsd.org/~gnn/oct_8_2024.pcapng>
> 
> I also note that an issue was raised on the forums that seems similar, way back 
> between FreeBSD 10 and 11:
> 
> https://forums.freebsd.org/threads/nfs-cache-misses-after-upgrading-to-11-1- 
> from-10-3.65491/ <https://forums.freebsd.org/threads/nfs-cache-misses-after- 
> upgrading-to-11-1-from-10-3.65491/>
> 
> I'm seeing this on 15 currentish (last few months).

Could it be just make checking for stale targets?
I.e., stat-ing various files to check their timestamps.


-- 
Andriy Gapon