On Sep 23, 2014, at 10:59 AM, Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> wrote: > On Sep 23, 2014, at 10:53 AM, Will Deacon <will.deacon@xxxxxxx> wrote: > >> On Tue, Sep 23, 2014 at 02:59:38PM +0100, Will Deacon wrote: >>> On Tue, Sep 23, 2014 at 02:33:06PM +0100, Weston Andros Adamson wrote: >>>> Any more info on how to reproduce this would be really great. Unfortunately I don’t >>>> have access to an arm64 system. >>> >>> I've not spotted a pattern other than using 64k pages, yet. If I manage to >>> get a reproducer, I'll let you know. >>> >>>> If it’s possible, could we get a packet trace around when this happens? This is pure >>>> speculation, but this might have something to do the resend path - a commit fails >>>> and all the requests on the commit list have to be resent. >>> >>> Sure, once I can reproduce it reliably, then I'll try to do that. >> >> Right, a bunch of DDing from /dev/zero over an ssh session triggers this >> very quickly. I've put a binary tcpdump here: >> >> http://www.willdeacon.ukfsn.org/bitbucket/oopsen/nfs/tcpdump.bin >> >> You may want to filter out the ssh packets. The only `interesting' thing to >> me is a retransmission about half way through, but I don't know what I'm >> looking for. >> >> The NFS server is 10.1.203.204 and the client is 10.1.203.24. > > Thanks! You are using NFSv2, so there are no commits - that rules out my hunch. Wait a second - the whole point of this extra reference (that the WARN_ON_ONCE is related to) is to handle the pass off to commit lists. Maybe I’m just doing the wrong thing here with NFSv2! More soon. -dros -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
