From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A270F55C05; Fri, 19 Jan 2024 17:45:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.55.52.88 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705686347; cv=none; b=Hhv2TQUl1U1kZHPpOWnf9+wYGDJJGcvzFUpcecbfntYgVcSdxKukvfFWpI+W6T1LjHozYrOjIRULlM6cYNM7hvpNOr+RxiMtMbQFb1iaQkrw+3yuu+wmBEhfGJJ5rGYHs3l7em2PArLlDOaJTVNo6ojgpXvkTKrNovm9IXnAQlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705686347; c=relaxed/simple; bh=uCvIEcJYYf5AbGoFG22DmOZZXGKEe8WB1ncLOJnDZs8=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=VI5IKVhQsN1Eokp+3/DvPYWA1UUMapSHXAPglpsKMc365l/F6lM3BNMsuP97YcllCzpsjk8bMdtIbU8rwZ9ZEBtNXgYx3YK6pYx1NO8rDlRvsheNrCTFSQfmN3iW5F6TXC6kQwH0IpDRAeTByLYBuF1hjeVzptoLeQAqnpUSQU8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=OgpYOQSU; arc=none smtp.client-ip=192.55.52.88 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="OgpYOQSU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705686345; x=1737222345; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=uCvIEcJYYf5AbGoFG22DmOZZXGKEe8WB1ncLOJnDZs8=; b=OgpYOQSUwAWCFxwegSueH5G21LHVZhGQuPbKVV1YHWawLZ7oj5VB2ArO k71icSrF+nWsDKLQIHzM47KvytgRPdrb9FLjpAPr80aGLXo1jAkP5khWh K8Vm/PMrz/n87HeT66WLHA5SVL+rBykCl+4QUZUSzy8fGJ3XL6s0uyevP nE29kojJKRZI5b5aBXcbhy6cMgigDe7NQRpzE5FF+Kb1qEmTdeHV7iuph ZJ/iC43bHgRi/F5QFVZpehmBXvt3TA5RlcGiRoOE+0zUW3wa5V3Tf3L61 9DG8vULwl3MJYs6HwmPSE4JW9pJSlaeB6kKVNoptNLT+xJ0jXwuGjnhGE Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10957"; a="431969498" X-IronPort-AV: E=Sophos;i="6.05,204,1701158400"; d="scan'208";a="431969498" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2024 09:45:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10957"; a="908371323" X-IronPort-AV: E=Sophos;i="6.05,204,1701158400"; d="scan'208";a="908371323" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.54.38.190]) by orsmga004.jf.intel.com with ESMTP; 19 Jan 2024 09:45:44 -0800 Received: by tassilo.localdomain (Postfix, from userid 1000) id 2C089302B79; Fri, 19 Jan 2024 09:45:44 -0800 (PST) From: Andi Kleen To: Ben Gainey Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, james.clark@arm.com Subject: Re: [PATCH 0/1] Support PERF_SAMPLE_READ with inherit_stat In-Reply-To: <20240119163924.2801678-1-ben.gainey@arm.com> (Ben Gainey's message of "Fri, 19 Jan 2024 16:39:23 +0000") References: <20240119163924.2801678-1-ben.gainey@arm.com> Date: Fri, 19 Jan 2024 09:45:44 -0800 Message-ID: <87a5p1kyif.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Ben Gainey writes: > In this configuration stream ids (such as may appear in the read_format > field of a PERF_RECORD_SAMPLE) are no longer globally unique, rather > the pair of (stream id, tid) uniquely identify each event. Tools that > rely on this, for example to calculate a delta between samples, would > need updating to take this into account. Previously valid event > configurations (system-wide, no-inherit and so on) where each stream id > is the identifier are unaffected. So is this an ABI break? It might need an optin, if it breaks anything, which wouldn't surprise me. We do have a lot of different perf stream parsers around these days and we cannot break them. -Andi