Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754254AbbG2WVT (ORCPT ); Wed, 29 Jul 2015 18:21:19 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:57532 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754214AbbG2WVR (ORCPT ); Wed, 29 Jul 2015 18:21:17 -0400 User-Agent: K-9 Mail for Android In-Reply-To: <1438201199-2809-1-git-send-email-Waiman.Long@hp.com> References: <1438201199-2809-1-git-send-email-Waiman.Long@hp.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 From: "Eric W. Biederman" Date: Wed, 29 Jul 2015 17:21:10 -0500 To: Waiman Long , Andrew Morton , Nicolas Dichtel , Al Viro , Alexey Dobriyan CC: linux-kernel@vger.kernel.org, Scott J Norton , Douglas Hatch Message-ID: X-XM-AID: U2FsdGVkX19DzaOVXo+UMbNYAiBbYkYg33KzJkwSf/A= X-SA-Exim-Connect-IP: 97.119.22.40 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.5 TooManyTo_004 Multiple "To" Header Recipients 5x (uncommon) * 0.6 TooManyTo_003 Multiple "To" Header Recipients 4x (uncommon) * 0.3 TooManyTo_001 Multiple "To" Header Recipients 2x (uncommon) * 0.5 TooManyTo_002 Multiple "To" Header Recipients 3x (uncommon) * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5004] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;Waiman Long ,Andrew Morton ,Nicolas Dichtel ,Al Viro ,Alexey Dobriyan X-Spam-Relay-Country: X-Spam-Timing: total 1279 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 3.9 (0.3%), b_tie_ro: 2.8 (0.2%), parse: 1.08 (0.1%), extract_message_metadata: 2.9 (0.2%), get_uri_detail_list: 0.46 (0.0%), tests_pri_-1000: 6 (0.5%), tests_pri_-950: 2.1 (0.2%), tests_pri_-900: 1.63 (0.1%), tests_pri_-400: 19 (1.5%), check_bayes: 17 (1.3%), b_tokenize: 6 (0.5%), b_tok_get_all: 4.0 (0.3%), b_comp_prob: 2.2 (0.2%), b_tok_touch_all: 2.0 (0.2%), b_finish: 0.92 (0.1%), tests_pri_0: 1214 (95.0%), tests_pri_500: 8 (0.7%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH] proc: change proc_subdir_lock to a rwlock X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 24 Sep 2014 11:00:52 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 511 Lines: 16 Two quick questions. - What motivates this work? Are you seeing lots of parallel reads on proc? - Why not rcu? Additions and removal of proc generic files is very rare. Conversion to rcu for reads should perform better and not take much more work. Eric -- 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/