From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Subject: Re: [v2 PATCH 0/2] rhashtable: rhashtable with duplicate objects
Date: Mon, 19 Sep 2016 12:58:37 +0200
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Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
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To: Herbert Xu <herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
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On Mon, 2016-09-19 at 18:48 +0800, Herbert Xu wrote:
> On Mon, Sep 19, 2016 at 12:10:27PM +0200, Johannes Berg wrote:
> > 
> > Btw, for debug I put
> > 
> > BUG_ON(atomic_read(&ht->nelems) < 0);
> > 
> > after the atomic_dec() in __rhashtable_remove_fast_one(). That
> > makes
> > the kernel crash instantly on the buggy code, and I just have to
> > run a
> > single test ("wpas_ctrl_interface_add_many") to get there.
> 
> Aha I see the problem now.  The nelems logic on remove is broken.

I looked at it for a long time, but didn't see it :) But yeah, I've
come to the same conclusion by adding debugging of the chains etc.

> I'll send out a v3.

I'll test it when I have it :)

johannes