--- Begin Message ---
- To: Debian Bug Tracking System <submit@bugs.debian.org>
- Subject: /usr/bin/ionice: kernel build with ionice -c3 can still disrupt disk i/o on same ext3 fs
- From: Arthur Marsh <arthur.marsh@internode.on.net>
- Date: Sat, 31 May 2014 09:46:05 +0930
- Message-id: <20140531001605.24414.98432.reportbug@am64.localdomain>
Package: util-linux
Version: 2.20.1-5.7
Severity: normal
File: /usr/bin/ionice
Dear Maintainer,
*** Reporter, please consider answering these questions, where appropriate ***
* What led up to the situation?
Using:
io scheduler cfq
ext3 filesystem on SATA hard disk
and building a kernel on a 4 core CPU system with CONCURRENCY_LEVEL=1
run under ionice -c3, during the linking stage of vmlinux:
LINK vmlinux
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/generated/compile.h
UPD include/generated/compile.h
CC init/version.o
LD init/built-in.o
KSYM .tmp_kallsyms1.o
KSYM .tmp_kallsyms2.o
LD vmlinux
the i/o of the kernel build still disrupts playback of files on the same ext3
filesystem using vlc, apparently due to disk i/o starvation of the vlc process.
main input error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 300 ms)
main input error: ES_OUT_RESET_PCR called
main input error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 368 ms)
main input error: ES_OUT_RESET_PCR called
main input error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 514 ms)
The video being played was 1280 x 720 resolution, using about 25 percent
of one CPU core, with a peak input bit rate of under 3 megabits per second,
and was started before the kernel build process and left running (ie not
paused).
* What exactly did you do (or not do) that was effective (or
ineffective)?
If I played a copy of the same media file on an ext3 filesystem on an
external USB hard disk I had no such problems.
If there were some command line readahead buffer option for vlc, I'd use that,
but this problem seems to be fairly disruptive.
Is there something deeper in the kernel that prioritises disk writes?
* What was the outcome of this action?
* What outcome did you expect instead?
*** End of the template - remove these template lines ***
-- System Information:
Debian Release: jessie/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 3.15.0-rc7+ (SMP w/4 CPU cores)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages util-linux depends on:
ii debconf [debconf-2.0] 1.5.53
ii dpkg 1.17.9
ii initscripts 2.88dsf-53
ii install-info 5.2.0.dfsg.1-3
ii libblkid1 2.20.1-5.7
ii libc6 2.18-7
ii libncurses5 5.9+20140118-1
ii libselinux1 2.3-1
ii libslang2 2.2.4-16
ii libtinfo5 5.9+20140118-1
ii libuuid1 2.20.1-5.7
ii lsb-base 4.1+Debian12
ii tzdata 2014d-1
ii zlib1g 1:1.2.8.dfsg-1
util-linux recommends no packages.
Versions of packages util-linux suggests:
ii dosfstools 3.0.26-2
ii kbd 1.15.5-1
ii util-linux-locales 2.20.1-5.7
-- debconf information:
util-linux/noauto-with-nonzero-passnum:
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