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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 30C68C63697 for ; Thu, 19 Nov 2020 16:33:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA0C120A8B for ; Thu, 19 Nov 2020 16:33:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="rBhQd/vY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728383AbgKSQde (ORCPT ); Thu, 19 Nov 2020 11:33:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727849AbgKSQde (ORCPT ); Thu, 19 Nov 2020 11:33:34 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 573DEC0613CF for ; Thu, 19 Nov 2020 08:33:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=E5I6TNShMUfYdB5NSaFer8UPB9kvSWVUKC2nL6ekt8I=; b=rBhQd/vYPRaUU9khhAK1P/vzwN 0QSz/V9FnrDwTlPMSEdFlAfDcETw/jSC1ueRjA3MlxR7wELE0HOSL85kVY2NQYdAv1V/7zYZT1JQ0 hCAkI4KkM2CohOxiZV1zivrD5d+txWDojEnMjwXPvPPISGe7+ByIrETQxow+GmnMNXTcdq8eat5iw 8azSBslnfgKTnk3TRhi3928nyPfCqvi7tXd429g/GyTzEVxLJxXBts/lIDwuODyo2d25DdEl1UCto dQVSjdg9fyh5IeSsDsxr1mHEq1NSgSS2sYKqOEce8mC2XuIpWgIEdQQg6G/rwiS67vVoBfhfsJTPu UXTsVswg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kfmsC-0006tp-TE; Thu, 19 Nov 2020 16:33:29 +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 AF6713011C6; Thu, 19 Nov 2020 17:33:27 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9AF002C36A0D3; Thu, 19 Nov 2020 17:33:27 +0100 (CET) Date: Thu, 19 Nov 2020 17:33:27 +0100 From: Peter Zijlstra To: David Howells Cc: paulmck@kernel.org, jlayton@redhat.com, willy@infradead.org, linux-cachefs@redhat.com, linux-kernel@vger.kernel.org Subject: Re: Can you help diagnose a weird failed wake? Message-ID: <20201119163327.GT3121392@hirez.programming.kicks-ass.net> References: <2220347.1605801222@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2220347.1605801222@warthog.procyon.org.uk> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 19, 2020 at 03:53:42PM +0000, David Howells wrote: > timeo = wait_var_event_timeout(&cookie->stage, cookie_stage_changed(cookie, stage), 10*HZ); > cookie->stage = stage; > changed = true; > break; > } > spin_unlock(&cookie->lock); > if (changed) { smp_mb(); // see comment on wake_up_bit() / wakequeue_active() > wake_up_var(&cookie->stage);