From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 21D8B85931; Wed, 30 Oct 2024 07:27:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730273238; cv=none; b=F3217uJtck8JWZho6ct4Z6PPoEv8MlDVc81K9qkHkblNb701SpQBSdaPw3YV00JgZaD40IYhzWso0EhXFZJiJllJdHpwbJEl+Es2PtIM/dRTeQPJyG0Kaf91zJ5PDDndE5O2YS533Pnnw2N9WmNWr19EvGd/RzajRwsySZTLNuE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730273238; c=relaxed/simple; bh=vGKU/9JKhIPRunU2sozlJwZTP3bFyVs8KZfKBAD/Evo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=IzFUHVVUoU46snSa8Nm1Cr2qXGw0obgtpj8c+nv0UCueWFCcyk/9m0PZFpZTAS1G5cPCrDIAGpjxdskb5u4FtnGMc9UPtgjQZPw9Fsw2Q6vEg8QsIT/RSNsCIqTsoDidgrI2DiWtfEUtC4Um/z3jb3FtqqPy94j4zbu32RsZCDc= 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=aZzOrWS4; arc=none smtp.client-ip=192.198.163.13 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="aZzOrWS4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730273236; x=1761809236; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=vGKU/9JKhIPRunU2sozlJwZTP3bFyVs8KZfKBAD/Evo=; b=aZzOrWS47uaYqWgaeFuBoFHBAjphsk9AACCGMbB7RO7C3OGTuiqTW+tq kYAhSNknvIywTJfu3hIjfMzPJmtDrls80rWybJ1qtmvB50DxIjpTG/+cI GFWmRd4dnmUOJCv1/w9bCTC1+n8tk82ZfLRr6WYLHOVH87eVd5kfAmm6m p1CK/cdQ+Rd0unyW/FuAhU1nA38wOCu0YouL6dlPtF6B6+9OWAAs9Fe+1 zOg0BYGXl07CWikwAXQuyVWcdz7jOYBIK65b9h2IQkyyhJaF3zgW6URr/ bmjSy9AbwGbt7Xn/Bur0nE+XTJHGTIlj0ueGWaHvAPZk7mLwTTR7Gimw6 A==; X-CSE-ConnectionGUID: HGu36LyMTyip0yVZ6h6edQ== X-CSE-MsgGUID: iEtchNlgSQy4TZE/x7SDpA== X-IronPort-AV: E=McAfee;i="6700,10204,11240"; a="32798747" X-IronPort-AV: E=Sophos;i="6.11,244,1725346800"; d="scan'208";a="32798747" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2024 00:27:02 -0700 X-CSE-ConnectionGUID: bryCe69USaeq6F6tP2Y8ZQ== X-CSE-MsgGUID: yxn/g556S2mCbJnJKJ7oFg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,244,1725346800"; d="scan'208";a="87359263" Received: from ubik.fi.intel.com (HELO localhost) ([10.237.72.184]) by orviesa004.jf.intel.com with ESMTP; 30 Oct 2024 00:26:56 -0700 From: Alexander Shishkin To: Li RongQing , peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, zhiquan1.li@intel.com, alexander.shishkin@linux.intel.com Cc: Li RongQing Subject: Re: [PATCH] perf/x86/intel/bts: allocate bts_ctx only if necessary In-Reply-To: <20241030063521.4025-1-lirongqing@baidu.com> References: <20241030063521.4025-1-lirongqing@baidu.com> Date: Wed, 30 Oct 2024 09:26:55 +0200 Message-ID: <87msimt5j4.fsf@ubik.fi.intel.com> 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 Li RongQing writes: > Avoid unnecessary per-CPU memory allocation on unsupported CPUs, > this can save 12K memory for every CPU Looks reasonable, but have you tested it? This driver is in serious danger of bitrot ever since KPTI. It might save even more if we simply remove the whole thing. Regards, -- Alex