After upgrading kernel from 3.10 to 3.14, we've observed sporadic messages "INFO: rcu_sched detected stalls on CPUs/tasks". Machines are either Xen dom0 or domU, xen version 4.3.2-r5. It happens on ordinary computers, on HP DL360G7 / HP DL360G8 hardware, on kernels 3.14.17-gentoo, 3.14.19-gentoo, 3.14.17-hardened, ext4/jfs/xfs. I once triggered the messages when running eix-sync on a dom0 with 3 domU in parallel. In the middle of the sync, all of the machines stopped responding for a while, so I killed the rsync and it went back to normal after a while. We're running kernel 3.14 on about 70 machines, I've observed these warnings mostly on database servers apart from the situation when running eix-sync (on the same machine 4 times - one on dom0, three on domUs). None of the machines crashed, but stopped responding for a while. It also happened on a database server (domU) where on a xen-dom0 running 3.10 and xen 4.3.1 we just upgraded the single domU to 3.14. So all that changed was the kernel on the domU, the dom0 remained on kernel 3.10.
Created attachment 385802 [details] kernel config-3.14.19-domU
Please post your `emerge --info' output in a comment.
Portage 2.2.8-r1 (default/linux/amd64/13.0, gcc-4.7.3, glibc-2.19-r1, 3.14.17-gentoo x86_64) ================================================================= System uname: Linux-3.14.17-gentoo-x86_64-Intel-R-_Xeon-R-_CPU_E5620_@_2.40GHz-with-gentoo-2.2 KiB Mem: 3555480 total, 2331912 free KiB Swap: 0 total, 0 free Timestamp of tree: Mon, 29 Sep 2014 10:15:01 +0000 ld GNU ld (Gentoo 2.23.2 p1.0) 2.23.2 app-shells/bash: 4.2_p50 dev-lang/python: 2.7.7, 3.3.5-r1 dev-util/cmake: 2.8.12.2-r1 dev-util/pkgconfig: 0.28-r1 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.12.4 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.69 sys-devel/automake: 1.13.4 sys-devel/binutils: 2.23.2 sys-devel/gcc: 4.7.3-r1 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4.2-r1 sys-devel/make: 3.82-r4 sys-kernel/linux-headers: 3.13 (virtual/os-headers) sys-libs/glibc: 2.19-r1 Repositories: gentoo ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-mtune=native -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-mtune=native -O2 -pipe" DISTDIR="/usr/portage/distfiles" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync" FFLAGS="-O2 -pipe" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j4" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" USE="acl amd64 berkdb bindist bzip2 cli cracklib crypt cxx dri fortran gdbm iconv mmx modules multilib ncurses nls nptl openmp pam pcre readline session sse sse2 ssl tcpd unicode zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_3" RUBY_TARGETS="ruby19 ruby20" USERLAND="GNU" VIDEO_CARDS="fbdev glint intel mach64 mga nouveau nv r128 radeon savage sis tdfx trident vesa via vmware dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON
Created attachment 385804 [details] dom0.txt dmesg on dom0
Created attachment 385806 [details] domu-db.txt dmesg on domU
Created attachment 385808 [details] domu-db2.txt dmesg on domU
Created attachment 385810 [details] domu-db3.txt dmesg on domU
Created attachment 385812 [details] domu-db.txt dmesg on domU
Created attachment 385814 [details] domu-rsync.txt dmesg on domU
Created attachment 385816 [details] domu-rsync2.txt dmesg on domU
Is this still an issue with later kernels or are you still on 3.14.17?
We have moved to >3.14.22, I've just checked all of the machines and it seems like the messages are gone.
Great news. I'll close for now, as this appears to be fixed.
