Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1163367AbbKTR2p (ORCPT ); Fri, 20 Nov 2015 12:28:45 -0500 Received: from orbit.nwl.cc ([176.31.251.142]:39496 "EHLO mail.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163259AbbKTR2o (ORCPT ); Fri, 20 Nov 2015 12:28:44 -0500 Date: Fri, 20 Nov 2015 18:28:41 +0100 From: Phil Sutter To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tgraf@suug.ch, fengguang.wu@intel.com, wfg@linux.intel.com, lkp@01.org Subject: Re: [PATCH v2 4/4] rhashtable-test: allow to retry even if -ENOMEM was returned Message-ID: <20151120172841.GD16648@orbit.nwl.cc> Mail-Followup-To: Phil Sutter , davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tgraf@suug.ch, fengguang.wu@intel.com, wfg@linux.intel.com, lkp@01.org References: <1448039840-11367-1-git-send-email-phil@nwl.cc> <1448039840-11367-5-git-send-email-phil@nwl.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448039840-11367-5-git-send-email-phil@nwl.cc> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 31 On Fri, Nov 20, 2015 at 06:17:20PM +0100, Phil Sutter wrote: > This is rather a hack to expose the current issue with rhashtable to > under high pressure sometimes return -ENOMEM even though system memory > is not exhausted and a consecutive insert may succeed. Please note that this problem does not show every time when running the test in default configuration on my system. With increased number of threads though, it becomes very visible. Load test_rhashtable like so: modprobe test_rhashtable enomem_retry=1 tcount=20 and grep dmesg for 'insertions retried after -ENOMEM'. In my case: # dmesg | grep -E '(insertions retried after -ENOMEM|Started)' | tail [ 34.642980] 1 insertions retried after -ENOMEM [ 34.642989] 1 insertions retried after -ENOMEM [ 34.642994] 1 insertions retried after -ENOMEM [ 34.648353] 28294 insertions retried after -ENOMEM [ 34.689687] 31262 insertions retried after -ENOMEM [ 34.714015] 16280 insertions retried after -ENOMEM [ 34.736019] 15327 insertions retried after -ENOMEM [ 34.755100] 39012 insertions retried after -ENOMEM [ 34.769116] 49369 insertions retried after -ENOMEM [ 35.387200] Started 20 threads, 0 failed Cheers, Phil -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/