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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,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 9C50AC17449 for ; Wed, 13 Nov 2019 10:29:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EEE1222C1 for ; Wed, 13 Nov 2019 10:29:23 +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="I/Ur/iFd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727487AbfKMK3W (ORCPT ); Wed, 13 Nov 2019 05:29:22 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:34742 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727298AbfKMK3T (ORCPT ); Wed, 13 Nov 2019 05:29:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Subject:Cc:To:From:Date:Message-Id: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=RyqyoAhYFrTj8+rZhJNjGKFC5lrfWOjpjDnyEauhCYw=; b=I/Ur/iFdUYGNFsS0rr+gF+gNu GOEklHUHCwoMZ6axDHJ5oa3WJo1Ldm32mWrVGG3YerY3bmjhbCbeR3AfoYxeW/E9mdJERKCS7DKvQ E5FcsH6lwx1fVNj1jrr9lploDJPQye3mazlabCoZbdqgSS5ztaKjdl7ypiG6gyOTFKOcCPXi+ODZy eIBeYDiu9QFvFJy3Xztf5SXf19EEr4OMGs6ZVRsuypvLdGh2Kr1hamfdlOpzR+aXKT1jyYZRnEhUa dowzsjtMZ1rqkdORTbm1ea2sSJtlu2gCCN/BiqeUl/81TNvi+39nJy3UvpyrhtDtlFzS+2mLxnBxB 9zTrk+H1g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iUptg-00073i-Be; Wed, 13 Nov 2019 10:29:12 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5D90330018B; Wed, 13 Nov 2019 11:28:01 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 934522026185B; Wed, 13 Nov 2019 11:29:08 +0100 (CET) Message-Id: <20191113102115.116470462@infradead.org> User-Agent: quilt/0.65 Date: Wed, 13 Nov 2019 11:21:15 +0100 From: Peter Zijlstra To: peterz@infradead.org, mingo@kernel.org, will@kernel.org Cc: oleg@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, juri.lelli@redhat.com, williams@redhat.com, bristot@redhat.com, longman@redhat.com, dave@stgolabs.net, jack@suse.com Subject: [PATCH 0/5] locking: Percpu-rwsem rewrite Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yet another version of the percpu-rwsem rewrite.. This one (ab)uses the waitqueue in an entirely different and unique way, but no longer shares it like it did. It retains the use of rcuwait for the writer-waiting-for-readers-to-complete condition. This one should be FIFO fair with writer-stealing. It seems to pass locktorture torture_type=percpu_rwsem_lock. But as always, this stuff is tricky, please look carefully.