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 8973BC4361B for ; Mon, 7 Dec 2020 15:21:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C39A23730 for ; Mon, 7 Dec 2020 15:21:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C39A23730 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=konsulko.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 98E208D0003; Mon, 7 Dec 2020 10:21:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 93F0A8D0001; Mon, 7 Dec 2020 10:21:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E1CA8D0003; Mon, 7 Dec 2020 10:21:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0008.hostedemail.com [216.40.44.8]) by kanga.kvack.org (Postfix) with ESMTP id 642A38D0001 for ; Mon, 7 Dec 2020 10:21:34 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 23A348249980 for ; Mon, 7 Dec 2020 15:21:34 +0000 (UTC) X-FDA: 77566850508.09.crate66_0900a71273df Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id EC489180AD81A for ; Mon, 7 Dec 2020 15:21:33 +0000 (UTC) X-HE-Tag: crate66_0900a71273df X-Filterd-Recvd-Size: 4476 Received: from mail-lf1-f42.google.com (mail-lf1-f42.google.com [209.85.167.42]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Mon, 7 Dec 2020 15:21:33 +0000 (UTC) Received: by mail-lf1-f42.google.com with SMTP id 23so5615786lfg.10 for ; Mon, 07 Dec 2020 07:21:33 -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=kPbs91xT74aN2J6nlwhCmX9RVbqzxOZbv6FPxQu9AXRfLjRBQguXTZGI4svo5saIQQ JIoqKOjaAcjcu4wxQCwmd4EDdVLqdK11N8bo4WDNPibdQdg3bb155HK1ocxnyc3BNL1B dAnvsxTTkXiF4kJl75I+Ao75HaBXAP4grb3GA41nK1VTJQPKRPoTv/VyvFg+z3B5bVtW /jw0EFYEroBUjg2wudsdqK9hmRB4RSuSn27cgBiLXLYQIsXAcXWu9qY5DQsJnt9+Krqe o7UVCdmm5Je+VpJ6YbjulC1eMTacCjHwbo6q5KCffq0QBPfGP8/RIcI3Uo5pk3cS4+p/ OP5w== X-Gm-Message-State: AOAM531Uxu3z3OCNNh4ahDjRA4wHN5I3S67bvI/tVhL9yhmivtgUfr3e gxHywQX6JsdOVz7sp/1gTGoFp8ySZBDgF4Nb8aIe3A== 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" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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