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From: Johannes Berg <johannes@sipsolutions.net>
To: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org
Cc: Thomas Graf <tgraf@suug.ch>, tom@herbertland.com
Subject: Re: Buggy rhashtable walking
Date: Fri, 05 Aug 2016 08:16:53 +0200	[thread overview]
Message-ID: <1470377813.2977.14.camel@sipsolutions.net> (raw)
In-Reply-To: <20160804074546.GA996@gondor.apana.org.au> (sfid-20160804_094611_627754_FBB091B2)


> So I'm going to fix this by consolidating identical objects into
> a single rhashtable entry which also lets us get rid of the
> insecure_elasticity setting.

Hm. Would you rather allocate a separate head entry for the hashtable,
or chain the entries?

(Luckily) the colliding key case practically never happens, and some
drivers don't even allow it, so that's perhaps something to keep in
mind for this. Perhaps we should just generally disallow it - but a few
people (hi Ben) would be really unhappy about that I guess.

I think this might affect more than one use of rhashtable in mac80211
now, since the mesh paths also use it.

johannes

  reply	other threads:[~2016-08-05  6:17 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-04  7:18 Buggy rhashtable walking Herbert Xu
     [not found] ` <20160804071846.GA773-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2016-08-04  7:45   ` Herbert Xu
2016-08-05  6:16     ` Johannes Berg [this message]
     [not found]       ` <1470377813.2977.14.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-08-05 10:48         ` Herbert Xu
2016-08-05 10:50           ` Johannes Berg
2016-08-05 11:46             ` Ben Greear
     [not found]               ` <57A47CA3.4010101-my8/4N5VtI7c+919tysfdA@public.gmane.org>
2016-08-08 15:26                 ` Herbert Xu
     [not found]             ` <1470394233.2977.37.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-18 13:50               ` [PATCH 0/2] rhashtable: rhashtable with duplicate objects Herbert Xu
2016-09-18 13:53                 ` [PATCH 1/2] rhashtable: Add rhlist interface Herbert Xu
2016-09-18 13:54                 ` [PATCH 2/2] mac80211: Use rhltable instead of rhashtable Herbert Xu
2016-09-19  8:20                 ` [PATCH 0/2] rhashtable: rhashtable with duplicate objects Johannes Berg
2016-09-19  8:25                   ` Johannes Berg
     [not found]                     ` <1474273518.4469.8.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19  8:35                       ` Herbert Xu
2016-09-19  8:58                         ` Johannes Berg
2016-09-19  8:40                 ` [v2 PATCH " Herbert Xu
2016-09-19  8:42                   ` [v2 PATCH 1/2] rhashtable: Add rhlist interface Herbert Xu
2016-09-19  8:42                   ` [v2 PATCH 2/2] mac80211: Use rhltable instead of rhashtable Herbert Xu
2016-09-19  9:15                   ` [v2 PATCH 0/2] rhashtable: rhashtable with duplicate objects Johannes Berg
     [not found]                     ` <1474276530.4469.16.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19  9:17                       ` Herbert Xu
2016-09-19  9:27                         ` Johannes Berg
2016-09-19  9:31                           ` Johannes Berg
     [not found]                           ` <1474277244.4469.21.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19  9:34                             ` Herbert Xu
     [not found]                               ` <20160919093434.GA12378-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2016-09-19  9:38                                 ` Johannes Berg
2016-09-19  9:50                               ` Johannes Berg
     [not found]                                 ` <1474278634.4469.25.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19  9:54                                   ` Johannes Berg
     [not found]                                     ` <1474278896.4469.26.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19 10:02                                       ` Johannes Berg
     [not found]                                         ` <1474279330.4469.28.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19 10:04                                           ` Johannes Berg
     [not found]                                             ` <1474279492.4469.29.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19 10:10                                               ` Johannes Berg
2016-09-19 10:48                                                 ` Herbert Xu
     [not found]                                                   ` <20160919104801.GA12774-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2016-09-19 10:58                                                     ` Johannes Berg
     [not found]                   ` <20160919084056.GA11875-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2016-09-19 10:58                     ` [v3 " Herbert Xu
2016-09-19 11:00                       ` [v3 PATCH 1/2] rhashtable: Add rhlist interface Herbert Xu
2016-09-19 21:16                         ` Thomas Graf
2016-09-20  1:52                           ` Herbert Xu
2016-09-19 11:00                       ` [v3 PATCH 2/2] mac80211: Use rhltable instead of rhashtable Herbert Xu
2016-09-19 11:03                       ` [v3 PATCH 0/2] rhashtable: rhashtable with duplicate objects Johannes Berg
     [not found]                         ` <1474283023.6544.0.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-19 11:32                           ` Johannes Berg
     [not found]                             ` <1474284732.6544.2.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2016-09-20  8:44                               ` David Miller

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