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=-5.7 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,URIBL_BLOCKED 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 A2145C197BF for ; Mon, 7 Dec 2020 15:22:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75760238E1 for ; Mon, 7 Dec 2020 15:22:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726596AbgLGPWN (ORCPT ); Mon, 7 Dec 2020 10:22:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726489AbgLGPWN (ORCPT ); Mon, 7 Dec 2020 10:22:13 -0500 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 032BFC06179C for ; Mon, 7 Dec 2020 07:21:33 -0800 (PST) Received: by mail-lf1-x129.google.com with SMTP id y19so6515979lfa.13 for ; Mon, 07 Dec 2020 07:21:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=konsulko.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ODpSoEmNbq4jUl3WGrBL/gHgU8LJBlKLzw2q3hitzfk=; b=EeF4TpNM5822R8wksasofMeoyAGWabpPMoSiBzdU/Ydxmhe4LTINP0VR/nGQwt7dtm 2vU6AyNCymAM+ZOq3UuxHO/kRnyq4yjfwo1yh2/VQacut+0XoV/wz9Vrp6e6u6Ccd3B2 LUwDHXYbCqBUKbu6Nyu0g6+VXnQ9BHEs8wBtk= 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=ODpSoEmNbq4jUl3WGrBL/gHgU8LJBlKLzw2q3hitzfk=; b=cCDiSoZV8ZH4bqgewqKACB64rmQzObm8htIhicEvQIEs0rgygo6qCm+0xlNqgpJcAY O8D68BJRXjy1Vg+WldKrFsYvhtX7puKutHiyaBNbiyppo6aPNtHCcjjh9F9EqC+pT9A9 TKKxol5k+poeo37EC1g/AN8JAI4VFrSoi19QoHEMu+r+wvVgZ8pKbbmzYme58bQujtTq HL+qaozBubpFCOF2B3Wf5Us+phN9rbtmhhCKH9uZPnP9qEN94xtmG9dTjk93q/0+S53h cDffgtPhVdV8STrSvfh3maLSoVbk03F45E1bCxYvbPGipME7u//sKxTHy66kyX8EvIMG ZS7A== X-Gm-Message-State: AOAM530oji8yq47o6siMtSF/xStoW7CKzYd+4A1GAERo0E3qJnzl1Upo pCJtwBM3y2Wdc3HaFtlUQ4i6XCyI7PEkOkKHvPor7q1KUCaGKNmZ X-Google-Smtp-Source: ABdhPJwHEC0oFuYU7tv2dbpbzD3yAaNJNYk53+CAspsxguKOIGKzL9HNaC3UZ29ttjNVccWUmOEKbNHVYH46OCKAx7E= X-Received: by 2002:a19:8a46:: with SMTP id m67mr8042040lfd.515.1607354491520; Mon, 07 Dec 2020 07:21:31 -0800 (PST) MIME-Version: 1.0 References: <90c4857c53b657147bfb71a281ece9839b0373c2.camel@gmx.de> <20201130132014.mlvxeyiub3fpwyw7@linutronix.de> <856b5cc2a3d4eb673743b52956bf1e60dcdf87a1.camel@gmx.de> <20201130145229.mhbkrfuvyctniaxi@linutronix.de> <05121515e73891ceb9e5caf64b6111fc8ff43fab.camel@gmx.de> <20201130160327.ov32m4rapk4h432a@linutronix.de> <20201202220826.5chy56mbgvrwmg3d@linutronix.de> <64ab382309c41ca5c7a601fc3efbb6d2a6e68602.camel@gmx.de> <20201203133934.37aotbdjnd36lrxv@linutronix.de> <10d5088861ba219f3f7cd657fc95b0bedc19010a.camel@gmx.de> <3ffed6172820f2e8e821e1b8817dbd0bdd693c26.camel@gmx.de> <3ec93680c6a27626b23e99d552aa778be7b2ecec.camel@gmx.de> In-Reply-To: <3ec93680c6a27626b23e99d552aa778be7b2ecec.camel@gmx.de> From: Vitaly Wool Date: Mon, 7 Dec 2020 16:21:20 +0100 Message-ID: Subject: Re: scheduling while atomic in z3fold To: Mike Galbraith Cc: Sebastian Andrzej Siewior , Oleksandr Natalenko , LKML , Linux-MM , Andrew Morton , Steven Rostedt , Thomas Gleixner , linux-rt-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 7, 2020 at 1:34 PM Mike Galbraith wrote: > > On Mon, 2020-12-07 at 12:52 +0100, Vitaly Wool wrote: > > > > Thanks. This trace beats me because I don't quite get how this could > > have happened. > > I swear there's a mythical creature loose in there somewhere ;-) > Everything looks just peachy up to the instant it goes boom, then you > find in the wreckage that which was most definitely NOT there just a > few ns ago. > > > Hitting write_unlock at line 341 would mean that HANDLES_ORPHANED bit > > is set but obviously it isn't. > > Could you please comment out the ".shrink = z3fold_zpool_shrink" line > > and retry? > > Unfortunately, that made zero difference. Okay, I suggest that you submit the patch that changes read_lock() to write_lock() in __release_z3fold_page() and I'll ack it then. I would like to rewrite the code so that write_lock is not necessary there but I don't want to hold you back and it isn't likely that I'll complete this today. Best regards, Vitaly