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 8DE00C4332E for ; Sat, 21 Mar 2020 10:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6291820754 for ; Sat, 21 Mar 2020 10:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728083AbgCUKmP (ORCPT ); Sat, 21 Mar 2020 06:42:15 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:37993 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726607AbgCUKmP (ORCPT ); Sat, 21 Mar 2020 06:42:15 -0400 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jFbZX-0001a5-00; Sat, 21 Mar 2020 11:41:43 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 5D7DDFFC8D; Sat, 21 Mar 2020 11:41:42 +0100 (CET) From: Thomas Gleixner To: Christoph Hellwig Cc: LKML , Randy Dunlap , Peter Zijlstra , linux-pci@vger.kernel.org, Sebastian Andrzej Siewior , netdev@vger.kernel.org, Joel Fernandes , Will Deacon , Ingo Molnar , Davidlohr Bueso , "Paul E . McKenney" , Logan Gunthorpe , Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, Steven Rostedt , Bjorn Helgaas , Kurt Schwemmer , Kalle Valo , Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, Oleg Nesterov , Linus Torvalds , "David S. Miller" Subject: Re: [patch V2 07/15] powerpc/ps3: Convert half completion to rcuwait In-Reply-To: <20200319100459.GA18506@infradead.org> References: <20200318204302.693307984@linutronix.de> <20200318204408.102694393@linutronix.de> <20200319100459.GA18506@infradead.org> Date: Sat, 21 Mar 2020 11:41:42 +0100 Message-ID: <8736a2rnvd.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Christoph Hellwig writes: > On Wed, Mar 18, 2020 at 09:43:09PM +0100, Thomas Gleixner wrote: >> The PS3 notification interrupt and kthread use a hacked up completion to >> communicate. Since we're wanting to change the completion implementation and >> this is abuse anyway, replace it with a simple rcuwait since there is only ever >> the one waiter. >> >> AFAICT the kthread uses TASK_INTERRUPTIBLE to not increase loadavg, kthreads >> cannot receive signals by default and this one doesn't look different. Use >> TASK_IDLE instead. > > I think the right fix here is to jut convert the thing to a threaded > interrupt handler and kill off the stupid kthread. That'd be a major surgery. > But I wonder how alive the whole PS3 support is to start with.. There seem to be a few enthusiast left which have a Other-OS capable PS3 Thanks, tglx