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 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 9E00EECE59D for ; Tue, 15 Oct 2019 22:33:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70C982064B for ; Tue, 15 Oct 2019 22:33:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732135AbfJOWdW (ORCPT ); Tue, 15 Oct 2019 18:33:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58930 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732040AbfJOWdV (ORCPT ); Tue, 15 Oct 2019 18:33:21 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 196FD10F2E82; Tue, 15 Oct 2019 22:33:21 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-121-84.rdu2.redhat.com [10.10.121.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id BB0FA1001938; Tue, 15 Oct 2019 22:33:17 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <157117606853.15019.15459271147790470307.stgit@warthog.procyon.org.uk> <157117608708.15019.1998141309054662114.stgit@warthog.procyon.org.uk> To: Linus Torvalds Cc: dhowells@redhat.com, Tim Chen , Kan Liang , Casey Schaufler , Stephen Smalley , Greg Kroah-Hartman , Nicolas Dichtel , raven@themaw.net, Christian Brauner , keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-block , LSM List , linux-fsdevel , Linux API , Linux Kernel Mailing List Subject: Re: [RFC PATCH 02/21] Add a prelocked wake-up MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <20273.1571178796.1@warthog.procyon.org.uk> Date: Tue, 15 Oct 2019 23:33:16 +0100 Message-ID: <20274.1571178796@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.66]); Tue, 15 Oct 2019 22:33:21 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Linus Torvalds wrote: > > Add a wakeup call for a case whereby the caller already has the waitqueue > > spinlock held. > > That naming is crazy. Sorry, yeah. This is a bit hacked together at the moment and needs some more tidying up. I've had a lot of problems with performance regressions of up to 40% from seemingly simple changes involving moving locks around - it turns out that the problem was that I was running with kasan enabled. David