Received: by 2002:a25:c593:0:0:0:0:0 with SMTP id v141csp2179168ybe; Thu, 12 Sep 2019 05:51:57 -0700 (PDT) X-Google-Smtp-Source: APXvYqzxXX9PnJR9w/ZR/+89uvFzYGaHT2xkLoK/M7MTOtLcDA4r5g0fDI050Jk6N9gcUPckdM1+ X-Received: by 2002:aa7:cb4e:: with SMTP id w14mr40331874edt.230.1568292717060; Thu, 12 Sep 2019 05:51:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568292717; cv=none; d=google.com; s=arc-20160816; b=b4nlhoXLkSGmuCF8bWSnzsS9YsaHFlHTchgIrKXkbng5e0xArbtIigi+JakMeeKGlo XO1ksRE6jmUvtmNrzbXribY0+UQLf50E0sJ+9q22CDKwMmgw0cO5GvkloYK1MhkngIeT hJf6/1jyTDHYIviqO1o7TZPGkVq7wazAuVsQiSYxz/4XmQ0B0jKsQPcQZgC6l5w3aruF xUKfd68/e/HsNlBg3Bp3W1CRmKVtNcj9olhqu9czSVWxwXb1odo58XpkCWPAtxC+ro4K QznEsn8Hue4hvPcN57K8smbFdTimjVK1Ti6y3Zs2UArYOsPk6Tzdb4bg77mZQJfCrNhY KmkA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:date:subject:user-agent:message-id :references:cc:in-reply-to:from:to:content-transfer-encoding :mime-version; bh=XyDWTQm30jYw9UDYmVoOWxoAyQ5RsM1YmNY5ajoUcVc=; b=K2u6tS+aNh4Lrqg+QGMU0JZuc3UUEEw8DVq0zfvMIpQC3uAKpudZebbv2RUlRjllIT 60wKudjxz8Xz7kR3pQzed2ZiKGGVnmJM7znfBc0BJbdIrtix1A5VhaJeasp4uh1OkiIp LubxBfYFTYegZry0SHReEnmjf6Npd7NJbt2RO+KLnw00kOdnkp+cmLdpCh87Ijh1aDfI EJp0XwVqwIVM3GFIWti02f1t2ppQw2uNGHWzvFsnH+svvMeG791Wse+9ZstmGmNA2ECz wwC6yv7+OGuQaSeIYI4ABCCu1v3ZaD9AtAqY0mLf3bCGPSND7x1WVSMDJjSnlk0VF7tF MrXQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r23si12688775eji.295.2019.09.12.05.51.31; Thu, 12 Sep 2019 05:51:57 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731723AbfILMr5 convert rfc822-to-8bit (ORCPT + 99 others); Thu, 12 Sep 2019 08:47:57 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:65204 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730454AbfILMr4 (ORCPT ); Thu, 12 Sep 2019 08:47:56 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 18464153-1500050 for multiple; Thu, 12 Sep 2019 13:47:50 +0100 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT To: Linus Torvalds , Martin Wilck From: Chris Wilson In-Reply-To: Cc: Michal Koutny , "intel-gfx@lists.freedesktop.org" , "leho@kraav.com" , "tiwai@suse.de" , "linux-kernel@vger.kernel.org" References: <156535522344.29541.9312856809559678262@skylake-alporthouse-com> <20190910142047.GB3029@papaya> <3dcff41048621ff440687dd6691aae31a8647a1e.camel@suse.com> Message-ID: <156829246802.4926.7844021009098193103@skylake-alporthouse-com> User-Agent: alot/0.6 Subject: Re: 5.3-rc3: Frozen graphics with kcompactd migrating i915 pages Date: Thu, 12 Sep 2019 13:47:48 +0100 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Linus Torvalds (2019-09-12 12:59:25) > On Thu, Sep 12, 2019 at 12:51 PM Martin Wilck wrote: > > > > Is there an alternative to reverting aa56a292ce62 ("drm/i915/userptr: > > Acquire the page lock around set_page_dirty()")? And if we do, what > > would be the consequences? Would other patches need to be reverted, > > too? > > Looking at that commit, and the backtrace of the lockup, I think that > reverting it is the correct thing to do. > > You can't take the page lock in invalidate_range(), since it's called > from try_to_unmap(), which is called with the page lock already held. > > So commit aa56a292ce62 is just fundamentally completely wrong and > should be reverted. There's still the dilemma that we get called without the page lock, but at this moment in time in order to hit 5.3, it needs a revert sent directly to Linus. -Chris