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 0AF64ECAAD4 for ; Wed, 31 Aug 2022 20:07:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231837AbiHaUHh (ORCPT ); Wed, 31 Aug 2022 16:07:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbiHaUHe (ORCPT ); Wed, 31 Aug 2022 16:07:34 -0400 Received: from mail-oa1-x34.google.com (mail-oa1-x34.google.com [IPv6:2001:4860:4864:20::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 862BDC6964; Wed, 31 Aug 2022 13:07:33 -0700 (PDT) Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-11e7e0a63e2so25903675fac.4; Wed, 31 Aug 2022 13:07:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:references :in-reply-to:user-agent:subject:cc:to:from:date:from:to:cc; bh=FrnGJAg4fYCg1AP2pSGC4eTVKDTWelds3dMK140YAig=; b=F2RZ/kbcet2nnEjJuNUizC/5J0r4T31f0JF7s2UpgiOY/HHsZ2qJVekYU279tbpaV7 T+tZmix6IAloGB9aZMupJWe56mAiwS5Y7aw8RvKwkP1tRImaLvbPP2EO6kQfKF+2gKIU xBm4nvuA9yeO9zynS3PjoARLgRS7Venew++IH3Fzzz8hPOGonXy9a2HknniGv3aJZhBv 7rURkgJQWiGoMR2xsg2zuYW+plN8HbQtaKf0UIdHbwnUUUDE3geD54TeTLHYqunHO2B6 YvAy4Kpa+wyR/3BQiiYOiuD9rM5tG/u8UPZ+WfegBhSL215SW6mla4lxsN680Bf6XGz1 GzEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:references :in-reply-to:user-agent:subject:cc:to:from:date:x-gm-message-state :from:to:cc; bh=FrnGJAg4fYCg1AP2pSGC4eTVKDTWelds3dMK140YAig=; b=EV2kqrFX4k6UVXw0Kyg2R4TR0F4MEyclF9rNWoSXs9LNnd9/N1I7bb/Kn3SNKfPyxc Bh6P/EvwS6BGnNGHhTqgXcpEH3YzGnNDrLHql5KZ01jnmXiDsCHXs9OWcKR772YeGueV EifGVXHhRUWuP1PLlIGTkWZMv7w1hEvmcmPsZt5MkpCP1CWi9gzQJ1GfrgtEjEqWvKrw Cs7JI0811bCritat6cxkOQpXnB8etwuOsycAfLiaBYeNh+eI0SoNUKfixo/MStQT43Gm x4SGVc9NxmEV71Q69zsYEnkAmKw6JfiCARC1pmQ+8bdjchSBjdDYHC2/Tj1g6B2RnnO0 mcwA== X-Gm-Message-State: ACgBeo3B9x29Scb8T4M/TFTNR4T5HaSez95frNPGKKgbnWu2l+ElzhXJ 4XmGuCQPJfVWRUQtzSPQtz0= X-Google-Smtp-Source: AA6agR6p0fpsbFyUZPzFcYLr6TT2/7joPvqBfO2tIGHAZdb+YvUV+cNf3gOg1+5nBUh2JMFm16G0TQ== X-Received: by 2002:a05:6808:df1:b0:344:5db2:e25a with SMTP id g49-20020a0568080df100b003445db2e25amr1995689oic.1.1661976452663; Wed, 31 Aug 2022 13:07:32 -0700 (PDT) Received: from [127.0.0.1] ([187.19.239.32]) by smtp.gmail.com with ESMTPSA id c4-20020a9d6844000000b00636f7059b27sm9355348oto.5.2022.08.31.13.07.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 31 Aug 2022 13:07:31 -0700 (PDT) Date: Wed, 31 Aug 2022 17:07:25 -0300 From: Arnaldo Carvalho de Melo To: Rob Herring , Alexander Shishkin , Ingo Molnar , Catalin Marinas , Peter Zijlstra , Mark Rutland , Will Deacon , Jiri Olsa , Namhyung Kim , Arnaldo Carvalho de Melo CC: "linux-kernel@vger.kernel.org" , linux-arm-kernel , linux-perf-users Subject: Re: [PATCH RFC v1 2/3] perf: Add perf_event_attr::config3 User-Agent: K-9 Mail for Android In-Reply-To: References: <20220825-arm-spe-v8-7-v1-0-c75b8d92e692@kernel.org> <20220825-arm-spe-v8-7-v1-2-c75b8d92e692@kernel.org> Message-ID: <2295C0C0-6F55-4554-8062-D10BFED58323@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On August 31, 2022 4:06:40 PM GMT-03:00, Rob Herring w= rote: >On Thu, Aug 25, 2022 at 1:08 PM Rob Herring wrote: >> >> Arm SPEv1=2E2 adds another 64-bits of event filtering control=2E As the >> existing perf_event_attr::configN fields are all used up for SPE PMU, a= n >> additional field is needed=2E Add a new 'config3' field=2E > >In testing this, just exposing 'config3' in the format attributes >causes the SPE PMU to be disabled=2E So we can't add this without >breaking existing perf=2E Shouldn't perf just skip any format fields it >doesn't know about? Something it doesn't know about, even more at the main perf_event_attr lev= el, may preclude it to grok new records=2E "May" is the key word, as perf_event_hdr has a size field, maybe sometimes= it's possible to do as you say=2E If you're interested propose patches to make perf ignore things when possi= ble=2E - Arnaldo