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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 9EB35ECDE47 for ; Thu, 8 Nov 2018 15:25:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CBA020825 for ; Thu, 8 Nov 2018 15:25:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UHJJmx2N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CBA020825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726915AbeKIBBd (ORCPT ); Thu, 8 Nov 2018 20:01:33 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:33510 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726375AbeKIBBd (ORCPT ); Thu, 8 Nov 2018 20:01:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=wuBdvmBEI70uIvQdAA8obT6YBWRMuyuR1fcXdBf7kx4=; b=UHJJmx2NgqK/jWGcTEqd4LyHc Jzo88G6SObnNV9UwxL77+URbJkTRwOPWom9c+a0D2Rv52NX4h05JfEIzqfct02ePhU+2GhWML4efJ OLfDgV0LGni1MPMXDEALLEwRBUBw0CaLqnzK/bgnm5/0t8qDuW9AkiIj2hBuzq7CA90oyDTN2IjS2 YSeT80iugCiAtIpF+ZojQOIC1YEqMArtebKyi7N4+4ZEHsoNkSb+FtIqupVf9hGcHdAisPQibIZnS DZSSUTp7E3L3IMA2VEloyTz593rzllY2xv25Pkea4lqeXaIAsEMm4kH2bTfjfOwfDjnPknzdBwfUa OxaJKYn/g==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gKmBX-0008Ln-1K; Thu, 08 Nov 2018 15:25:31 +0000 Date: Thu, 8 Nov 2018 07:25:30 -0800 From: Christoph Hellwig To: Joakim Tjernlund Cc: "danielwa@cisco.com" , "dwmw2@infradead.org" , "linux-kernel@vger.kernel.org" , "nkela@cisco.com" , "linux-mtd@lists.infradead.org" , "xe-linux-external@cisco.com" Subject: Re: [PATCH] jffs2: implement mount option to configure endianness Message-ID: <20181108152530.GA27198@infradead.org> References: <20181106214928.40020-1-nkela@cisco.com> <921b0f78cf67d7307a0555e1fd6f2c2976310adc.camel@infradead.org> <1e4c066d1896e2a0b8b146253d34d05cc4f9ab36.camel@infinera.com> <8b08e8b992093453bb2b9caff8cff08c.squirrel@twosheds.infradead.org> <20181107173303.slnb3i2d6ufaonp7@zorba> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 07, 2018 at 06:41:47PM +0000, Joakim Tjernlund wrote: > > Certainly not. I'm not sure which architectures do have Spectre V2 > > mitigations which make indirect branches expensive now... perhaps there is > > no intersection with the cases where we really care about JFFS2 being > > CPU-bound? > > All that passing of a new extra arg and extra if .. elif .. does cost too. I know of no current microarchitecture where an indirect call is cheaper than a simple branch, which can be very well predicted.