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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3FFD6C3A5A6 for ; Sat, 31 Aug 2019 14:43:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 094B821874 for ; Sat, 31 Aug 2019 14:43:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728314AbfHaOnq (ORCPT ); Sat, 31 Aug 2019 10:43:46 -0400 Received: from ms.lwn.net ([45.79.88.28]:46752 "EHLO ms.lwn.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727905AbfHaOnq (ORCPT ); Sat, 31 Aug 2019 10:43:46 -0400 Received: from lwn.net (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 51A587DC; Sat, 31 Aug 2019 14:43:45 +0000 (UTC) Date: Sat, 31 Aug 2019 08:43:44 -0600 From: Jonathan Corbet To: Federico Vaga Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH] doc:lock: remove reference to clever use of read-write lock Message-ID: <20190831084344.6fd7c039@lwn.net> In-Reply-To: <20190831134116.25417-1-federico.vaga@vaga.pv.it> References: <20190831134116.25417-1-federico.vaga@vaga.pv.it> Organization: LWN.net MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 31 Aug 2019 15:41:16 +0200 Federico Vaga wrote: > several CPU's and you want to use spinlocks you can potentially use > -cheaper versions of the spinlocks. IFF you know that the spinlocks are > +cheaper versions of the spinlocks. If you know that the spinlocks are > never used in interrupt handlers, you can use the non-irq versions:: I suspect that was not actually a typo; "iff" is a way for the mathematically inclined to say "if and only if". jon