From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 6780F2806EF for ; Tue, 22 Aug 2017 18:55:34 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id z195so479228wmz.8 for ; Tue, 22 Aug 2017 15:55:34 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id x42si62167wrb.449.2017.08.22.15.55.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Aug 2017 15:55:33 -0700 (PDT) Date: Tue, 22 Aug 2017 15:55:30 -0700 From: Andrew Morton Subject: Re: [Bug 196729] New: System becomes unresponsive when swapping - Regression since 4.10.x Message-Id: <20170822155530.928b377fa636bbea28e1d4df@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: netwiz@crc.id.au, bugzilla-daemon@bugzilla.kernel.org (switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Tue, 22 Aug 2017 11:17:08 +0000 bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=196729 > > Bug ID: 196729 > Summary: System becomes unresponsive when swapping - Regression > since 4.10.x > Product: Memory Management > Version: 2.5 > Kernel Version: 4.11.x / 4.12.x > Hardware: All > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Page Allocator > Assignee: akpm@linux-foundation.org > Reporter: netwiz@crc.id.au > Regression: No So it's "Regression: yes". More info at the bugzilla link. > I have 10Gb of RAM in this system and run Fedora 26. If I launch Cities: > Skylines with no swap space, things run well performance wise until I get an > OOM - and it all dies - which is expected. > > When I turn on swap to /dev/sda2 which resides on an SSD, I get complete > system freezes while swap is being accessed. > > The first swap was after loading a saved game, then launching kmail in the > background. This caused ~500Mb to be swapped to /dev/sda2 on an SSD. The > system froze for about 8 minutes - barely being able to move the mouse. The > HDD LED was on constantly during the entire time. > > To hopefully rule out the above glibc issue, I started the game via jemalloc - > but experienced even more severe freezes while swapping. I gave up waiting > after 13 minutes of non-responsiveness - not even being able to move the mouse > properly. > > During these hangs, I could typed into a Konsole window, and some of the > typing took 3+ minutes to display on the screen (yay for buffers?). > > I have tested this with both the default vm.swappiness values, as well as the > following: > vm.swappiness = 1 > vm.min_free_kbytes = 32768 > vm.vfs_cache_pressure = 60 > > I noticed that when I do eventually get screen updates, all 8 cpus (4 cores / > 2 threads) show 100% CPU usage - and kswapd is right up there in the process > list for CPU usage. Sadly I haven't been able to capture this information > fully yet due to said unresponsiveness. > > (more to come in comments & attachments) > > -- > You are receiving this mail because: > You are the assignee for the bug. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org