From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48382) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gWpdc-0001Pv-Ly for qemu-devel@nongnu.org; Tue, 11 Dec 2018 16:32:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gWpdZ-0000fl-GQ for qemu-devel@nongnu.org; Tue, 11 Dec 2018 16:32:20 -0500 Received: from mail-oi1-x241.google.com ([2607:f8b0:4864:20::241]:44902) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gWpdZ-0000fS-0p for qemu-devel@nongnu.org; Tue, 11 Dec 2018 16:32:17 -0500 Received: by mail-oi1-x241.google.com with SMTP id m6so13269298oig.11 for ; Tue, 11 Dec 2018 13:32:16 -0800 (PST) References: <20181207085635.4291-1-mark.cave-ayland@ilande.co.uk> <20181210025943.GE4261@umbus.fritz.box> <20181211012027.GA4261@umbus.fritz.box> <7bcfc7ae-7777-e1e5-d1a4-36c2d958b845@ilande.co.uk> From: Richard Henderson Message-ID: Date: Tue, 11 Dec 2018 15:32:11 -0600 MIME-Version: 1.0 In-Reply-To: <7bcfc7ae-7777-e1e5-d1a4-36c2d958b845@ilande.co.uk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-ppc] [RFC PATCH 0/6] target/ppc: convert VMX instructions to use TCG vector operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark Cave-Ayland , David Gibson , BALATON Zoltan Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org On 12/11/18 1:35 PM, Mark Cave-Ayland wrote: > Looking at your profiles above, the primary hotspot appears to be > helper_lookup_tb_ptr(). However as someone quite new to the TCG parts of QEMU, I > couldn't tell you whether or not this is to be expected. > > Perhaps a question for Richard: what could we consider to be a "normal" backend when > looking at profiles in terms of recommended features to implement, and to get an idea > of what a typical profile should look like? > > It would be interesting to compare with a similar workload profile on e.g. ARM to see > if there is anything obvious that stands out for PPC. For Alpha, which has relatively sane tlb management, the top entry in the profile is helper_lookup_tb_ptr at about 8%. Otherwise, somewhere in the top 2 or 3 functions will be helper_le_ldq_mmu at about 2%. That's probably a best-case scenario. r~