From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DD97C43381 for ; Thu, 21 Mar 2019 20:58:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44A9C218D3 for ; Thu, 21 Mar 2019 20:58:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbfCUU6Q (ORCPT ); Thu, 21 Mar 2019 16:58:16 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:53214 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726370AbfCUU6P (ORCPT ); Thu, 21 Mar 2019 16:58:15 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id D1C7D133E9775; Thu, 21 Mar 2019 13:58:14 -0700 (PDT) Date: Thu, 21 Mar 2019 13:58:14 -0700 (PDT) Message-Id: <20190321.135814.680505348166965154.davem@davemloft.net> To: herbert@gondor.apana.org.au Cc: joshhunt00@gmail.com, jelsasser@appneta.com, tgraf@suug.ch, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [v3 PATCH] rhashtable: Still do rehash when we get EEXIST From: David Miller In-Reply-To: <20190321013952.3quw6bsqptyngzo5@gondor.apana.org.au> References: <20190321013952.3quw6bsqptyngzo5@gondor.apana.org.au> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 21 Mar 2019 13:58:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Herbert Xu Date: Thu, 21 Mar 2019 09:39:52 +0800 > As it stands if a shrink is delayed because of an outstanding > rehash, we will go into a rescheduling loop without ever doing > the rehash. > > This patch fixes this by still carrying out the rehash and then > rescheduling so that we can shrink after the completion of the > rehash should it still be necessary. > > The return value of EEXIST captures this case and other cases > (e.g., another thread expanded/rehashed the table at the same > time) where we should still proceed with the rehash. > > Fixes: da20420f83ea ("rhashtable: Add nested tables") > Reported-by: Josh Elsasser > Signed-off-by: Herbert Xu Applied and queued up for -stable, thanks Herbert.