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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D38FCC77B62 for ; Tue, 4 Apr 2023 17:29:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236034AbjDDR3d (ORCPT ); Tue, 4 Apr 2023 13:29:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232492AbjDDR3O (ORCPT ); Tue, 4 Apr 2023 13:29:14 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37CB47A91; Tue, 4 Apr 2023 10:27:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680629252; x=1712165252; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=tDN5YPkV/esR+g1oRg0BfEw5XkDORzws27KDzqyGeIA=; b=PLgrHNC39H2v0fH8yu3tDqqhWtnbTuJ1z++nN+Xjj+WcgPgllh76Hn4p TIOl0LUfLnL7F7Cx6UsBp6wTxMGgauMFvNLXFqRVfDWm0jpjC7eUhD43n q+wpzaZSEUI+ta+wuO2cBN5q0bsMdbdPA/IhhN/uGwFd/xajxVoyhAgxY lcRjEvp/yqlsJ8qyRgUGJ+JcWKgi2txUyQnEah4ReQeM03KSup4E8fYjH JDUi3Vn6zQYpzTBAdiV/q1U57567ZqnUM1j2Fa6xoE59D8qlHR01ymIxJ QORsu4SP9qDH0z7CAE0oPHHI48Il5pbSwfen0V8KPV1pu3Egt956gYFAm Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10670"; a="343960865" X-IronPort-AV: E=Sophos;i="5.98,318,1673942400"; d="scan'208";a="343960865" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2023 10:25:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10670"; a="688976704" X-IronPort-AV: E=Sophos;i="5.98,318,1673942400"; d="scan'208";a="688976704" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.249.33.86]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2023 10:25:46 -0700 Message-ID: <7443d427-783b-44b6-85e6-5e667bb83a94@intel.com> Date: Tue, 4 Apr 2023 20:25:41 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.9.1 Subject: Re: [PATCH v5 00/17] Reference count checker and related fixes Content-Language: en-US To: Ian Rogers , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Darren Hart , Davidlohr Bueso , James Clark , John Garry , Riccardo Mancini , Yury Norov , Andy Shevchenko , Andrew Morton , Leo Yan , Andi Kleen , Thomas Richter , Kan Liang , Madhavan Srinivasan , Shunsuke Nakamura , Song Liu , Masami Hiramatsu , Steven Rostedt , Miaoqian Lin , Stephen Brennan , Kajol Jain , Alexey Bayduraev , German Gomez , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Dumazet , Dmitry Vyukov , Hao Luo Cc: Stephane Eranian References: <20230320212248.1175731-1-irogers@google.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/04/23 18:58, Ian Rogers wrote: > Ping. It would be nice to have this landed or at least the first 10 > patches that refactor the map API and are the bulk of the > lines-of-code changed. Having those landed would make it easier to > rebase in the future, but I also think the whole series is ready to > go. I was wondering if the handling of dynamic data like struct map makes any sense at present. Perhaps someone can reassure me. A struct map can be updated when an MMAP event is processed. So it seems like anything racing with event processing is already broken, and reference counting / locking cannot help - unless there is also copy-on-write (which there isn't at present)? For struct maps, referencing it while simultaneously processing events seems to make even less sense?