Received: by 2002:a25:8b12:0:0:0:0:0 with SMTP id i18csp273385ybl; Fri, 9 Aug 2019 05:54:56 -0700 (PDT) X-Google-Smtp-Source: APXvYqxL/WMFtLji1GyWEFnU31oS/MZbW2XCCRm3Mzvbh2KLP1mX8/Q7hsswmEMH4DNWllXQ2cZR X-Received: by 2002:a63:ff20:: with SMTP id k32mr17394557pgi.445.1565355296225; Fri, 09 Aug 2019 05:54:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565355296; cv=none; d=google.com; s=arc-20160816; b=aISy8xCMNd8qXmTsi3vMw09xZH6CeLCDFXvX3RyG+eS5ltvGAFgvkW/EAY86AVqCHJ cP5CnrtKjIk38jsDTq1xfT8P+6KfjQzODTxRhik5yca+K9oi4OCaKoT2EuWwbpRmwKEm bzhV4tuxTxH19JsdOXH//iD3LivC97g17F3a5ZuvbHBAlA0qP84DNCuNwZtIh/wu5Zhv 0ZbzSgJ4DdfOjmMYEFUeBd+pFmOS/n1WR2SxqPdgHrUGPQHkaao5nMVz7R3+1AyTThyl zrgPVimtGfccN7zUoY12ZmWe8N7MoC4MotgUeI1M36JCymKupiiS/ad5OA6GhOhWkz/f DhGw== 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=edQ9tYVU4JF7ewHJnFvf6EY0bA8X0I9v2RvjwRudsr4=; b=FFHeR8W6UL5kow3Xbsg3gG/OTCpZRJpjNsoZrFTBDBBx8+UJDbrDOMQZ58ufk13xAk 9RW8MV0cIY0x9aAEeLpptzQEXl/BJ+zYGYBbuD8+TRrwXVfdBGvwIB+n7nuXbhSihI9g D4gZy9+renlEpodU7H/ZEcsWJ6KTFaZJsVnOLro1Mupn4aYeYZkqQVIuozxBBwP9Iz7d kGXWV+g9VQpLXCpiBP3KiUTFAKK49ht4HVqYZY1gmaP2p8t40hGd/SBYL5D06lVrli0H m7WGyUVM2WGiJk4kX7guFqJwusE03BYgqCH3JDX+aWp740zvSG6U4FkPGkdD4QH7WtB6 K1pA== 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 j5si2161761pjn.27.2019.08.09.05.54.40; Fri, 09 Aug 2019 05:54:56 -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 S2406881AbfHIMxx convert rfc822-to-8bit (ORCPT + 99 others); Fri, 9 Aug 2019 08:53:53 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:51995 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726091AbfHIMxw (ORCPT ); Fri, 9 Aug 2019 08:53:52 -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 17943319-1500050 for multiple; Fri, 09 Aug 2019 13:53:46 +0100 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT To: "intel-gfx@lists.freedesktop.org" , Martin Wilck From: Chris Wilson In-Reply-To: Cc: "linux-kernel@vger.kernel.org" References: Message-ID: <156535522344.29541.9312856809559678262@skylake-alporthouse-com> User-Agent: alot/0.6 Subject: Re: 5.3-rc3: Frozen graphics with kcompactd migrating i915 pages Date: Fri, 09 Aug 2019 13:53:43 +0100 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Martin Wilck (2019-08-09 13:41:42) > This happened to me today, running kernel 5.3.0-rc3-1.g571863b-default > (5.3-rc3 with just a few patches on top), after starting a KVM virtual > machine. The X screen was frozen. Remote login via ssh was still > possible, thus I was able to retrieve basic logs. > > sysrq-w showed two blocked processes (kcompactd0 and KVM). After a > minute, the same two processes were still blocked. KVM seems to try to > acquire a lock that kcompactd is holding. kcompactd is waiting for IO > to complete on pages owned by the i915 driver. My bad, it's known. We haven't decided on whether to revert the unfortunate recursive locking (and so hit another warn elsewhere) or to ignore the dirty pages (and so risk losing data across swap). cb6d7c7dc7ff ("drm/i915/userptr: Acquire the page lock around set_page_dirty()") -Chris