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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C259BC10F14 for ; Thu, 3 Oct 2019 05:52:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EC3D222C3 for ; Thu, 3 Oct 2019 05:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570081957; bh=PMscm+0DA539pxL/O1xC58O5vmGdw+fjyf0hSC501JA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=0CAIQibTw6Ks5PHC/rC67pOj4RdJIrxFN1L4C4Nh735hAYom7BD8Bf69syQEdB5/w zrcXY0l2noUJrUx1CApe3gtBh99EVFQJk72leooXhgtxOwrHMNMevieIcE/XC3c7/A MZrBnufDvPlJynNghvUM6nmVwA4Resms1pK6u3dU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728079AbfJCFwg (ORCPT ); Thu, 3 Oct 2019 01:52:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:45882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725999AbfJCFwg (ORCPT ); Thu, 3 Oct 2019 01:52:36 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CBDAD21D81; Thu, 3 Oct 2019 05:52:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570081955; bh=PMscm+0DA539pxL/O1xC58O5vmGdw+fjyf0hSC501JA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=p/g7tnZel4tqLj0Fvhp44zo//DejCr9pc+aN5RlVl1GEc8HmPxnbxdEwtTyGEmdMx 9Gt5n+KUpDs9XNEnnBT+uBNfh4PNrukZ49LLkStS0okjmYFVdQWlZKAB3sUh1fZ4+G N1HzrzsoLSdU48rnWApHoVPvID4oegB2EADzJCyc= Date: Thu, 3 Oct 2019 14:52:30 +0900 From: Masami Hiramatsu To: Daniel Bristot de Oliveira Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, x86@kernel.org, Nadav Amit , Andy Lutomirski , Dave Hansen , Song Liu , Masami Hiramatsu , Steven Rostedt Subject: Re: [PATCH 3/3] x86/ftrace: Use text_poke() Message-Id: <20191003145230.fe8314d8575c2f88b16322e8@kernel.org> In-Reply-To: References: <20190827180622.159326993@infradead.org> <20190827181147.166658077@infradead.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2 Oct 2019 18:35:26 +0200 Daniel Bristot de Oliveira wrote: > ftrace was already batching the updates, for instance, causing 3 IPIs to enable > all functions. The text_poke() batching also works. But because of the limited > buffer [ see the reply to the patch 2/3 ], it is flushing the buffer during the > operation, causing more IPIs than the previous code. Using the 5.4-rc1 in a VM, > when enabling the function tracer, I see 250+ intermediate text_poke_finish() > because of a full buffer... Would you have any performance numbers of the previous code and applying this? Thank you, -- Masami Hiramatsu