Re: CVS commit: src/sys/netinet

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Fri, Dec 29, 2017 at 4:37 AM, Chuck Silvers <chuq%chuq.com@localhost> wrote:
> On Thu, Dec 28, 2017 at 05:34:27PM +0900, Ryota Ozaki wrote:
>> On Thu, Dec 28, 2017 at 5:05 PM, Tom Ivar Helbekkmo
>> <tih%hamartun.priv.no@localhost> wrote:
>> > Ryota Ozaki <ozaki-r%NetBSD.org@localhost> writes:
>> >
>> >> I think the below patch fixes the above issue, but probably
>> >> there is a better solution.
>> >
>> > Looks like didn't -- it just changed it a little bit.  Just like the
>> > last time, the hang happened while reading email over IMAP, which
>> > exercises disk and network at the same time, while the machine was busy
>> > doing a parallellized system build in the background.  This time,
>> > though, I got a core dump.  Here's the hang (the active process on this
>> > CPU is the IMAP server):
>>
>> Oh, my patch failed to keep SPL at IPL_VM because mutex_exit
>> tries to restore an SPL where mutex_enter is called. So I had to
>> put splvm before mutex_enter. Could you try the 2nd patch:
>>   http://www.netbsd.org/~ozaki-r/fix-pool_catchup.diff
>
> let's not mix explicit spl* calls with mutexes... even if that works
> in this particular case, it doesn't seem like a good practice in general.
> I was hoping to commit a different fix for this yesterday but I ran out of time.
> I should have time this evening to get back to this.

Yeah, so I hoped a better fix.

Anyway a fix for the issue was committed:
  http://cvsweb.netbsd.org/cgi-bin/cvsweb.cgi/src/sys/kern/subr_pool.c#rev1.220

Thanks,
  ozaki-r