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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 BAABFC43381 for ; Thu, 14 Feb 2019 10:55:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 917BC222A4 for ; Thu, 14 Feb 2019 10:55:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406794AbfBNKzC (ORCPT ); Thu, 14 Feb 2019 05:55:02 -0500 Received: from mail-ua1-f65.google.com ([209.85.222.65]:44746 "EHLO mail-ua1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726989AbfBNKzB (ORCPT ); Thu, 14 Feb 2019 05:55:01 -0500 Received: by mail-ua1-f65.google.com with SMTP id v9so1851925uar.11; Thu, 14 Feb 2019 02:55:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0FVphaqkdujewH8xkqyrrOZQTGaRwWmRxSe5PedLOc8=; b=ApYz43ByVofkEJWVfKYyk4mg/Hem48JeMOp0K1FrY6011sgPSwT1KcTNuZqFKJKrBw Bsinxsz5Ci/BeC5nPX3xTlIfYS9+crpLBE6j+mr3pEpAVhjHr/9r23hFiaPP69kgUAqc uZRlR0YhtBuePPAqVn/bXl12oOnV+9YV+8zNPvDm6TFMEc4VNPX+mu6ZEjhUOj41Mghv 8eiAJ43tzmB3XZ7OkOaTfxh8BxeS+/cyay1b+GwTk1SWVASYYsxQWFs6XQwq0ks1iybT uZ/7PIGzcv3tLNXX5EPBXgP0EeamNy9BSuaOA8sekru2j/tZlfToCkK6bioRA5YPdwqy mNgA== X-Gm-Message-State: AHQUAubkNxFKl5hZ2Vaa8JTysdtdBdznb0W2d+q/l2bf9Zd6dXHR2UqM B83TDzlO+m9XWOpftQCwppQqjFWsmVtZwQm35G5gF8fz X-Google-Smtp-Source: AHgI3IbzhzuzEySYHwSbJTqDaXLapQMTOW53oPTxOn4RxgH5lrV4tpWGJZxYzqt5buLzgH3+IW1GydrsaXAApWWXHYU= X-Received: by 2002:a9f:2726:: with SMTP id a35mr1587802uaa.75.1550141699426; Thu, 14 Feb 2019 02:54:59 -0800 (PST) MIME-Version: 1.0 References: <1550095217-12047-1-git-send-email-longman@redhat.com> <1550095217-12047-3-git-send-email-longman@redhat.com> In-Reply-To: <1550095217-12047-3-git-send-email-longman@redhat.com> From: Geert Uytterhoeven Date: Thu, 14 Feb 2019 11:54:47 +0100 Message-ID: Subject: Re: [PATCH v4 2/3] locking/rwsem: Remove rwsem-spinlock.c & use rwsem-xadd.c for all archs To: Waiman Long , Christoph Hellwig Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner , "linux-ia64@vger.kernel.org" , Linux-sh list , linux-mips@vger.kernel.org, "H. Peter Anvin" , sparclinux , linux-riscv@lists.infradead.org, Linux-Arch , linux-s390 , Davidlohr Bueso , linux-c6x-dev@linux-c6x.org, "open list:QUALCOMM HEXAGON..." , "the arch/x86 maintainers" , "moderated list:H8/300 ARCHITECTURE" , linux-xtensa@linux-xtensa.org, Arnd Bergmann , linux-um@lists.infradead.org, linux-m68k , Openrisc , Borislav Petkov , Linux ARM , Tim Chen , Parisc List , Linus Torvalds , Linux Kernel Mailing List , alpha , nios2-dev@lists.rocketboards.org, Andrew Morton , linuxppc-dev Content-Type: text/plain; charset="UTF-8" Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Wed, Feb 13, 2019 at 11:01 PM Waiman Long wrote: > Currently, we have two different implementation of rwsem: > 1) CONFIG_RWSEM_GENERIC_SPINLOCK (rwsem-spinlock.c) > 2) CONFIG_RWSEM_XCHGADD_ALGORITHM (rwsem-xadd.c) > > As we are going to use a single generic implementation for rwsem-xadd.c > and no architecture-specific code will be needed, there is no point > in keeping two different implementations of rwsem. In most cases, the > performance of rwsem-spinlock.c will be worse. It also doesn't get all > the performance tuning and optimizations that had been implemented in > rwsem-xadd.c over the years. > > For simplication, we are going to remove rwsem-spinlock.c and make all > architectures use a single implementation of rwsem - rwsem-xadd.c. > > All references to RWSEM_GENERIC_SPINLOCK and RWSEM_XCHGADD_ALGORITHM > in the code are removed. > > Suggested-by: Peter Zijlstra > Signed-off-by: Waiman Long Note that this conflicts with "[PATCH 03/11] kernel/locks: consolidate RWSEM_GENERIC_* options" https://lore.kernel.org/lkml/20190213174005.28785-4-hch@lst.de/ Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds