Fermín Galán Márquez
2007-Apr-17 11:34 UTC
[Xen-users] 4gb seg fixup errors in Debian (usual hints don''t seem to work)
Hello, I''m getting a lot of "4gb seg fixup error" messages in the console of my domU, that I would like to avoid (not only due to "aesthetic", it impacts the performance, as explained at http://wiki.xensource.com/xenwiki/XenFaq#head-e05786f1e0d6a833bc146a6096cab2 d96f2b30ae). E.g.: 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc5f0 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc570 4gb seg fixup, process klogd (pid 1113), cs:ip 73:b7e2e5f0 4gb seg fixup, process klogd (pid 1113), cs:ip 73:b7eafd10 printk: 38 messages suppressed. 4gb seg fixup, process named (pid 1128), cs:ip 73:b7bc5c1c I''ve read some hints to solve the problem: - The "echo ''hwcap 0 nosegneg'' > /etc/ld.so.conf.d/libc6-xen.conf" procedure http://lists.xensource.com/archives/html/xen-users/2006-11/msg00056.html - The xen-divert-tls-libc script http://wiki.xensource.com/xenwiki/DebianTlsLibcDiversion - The "mv /lib/tls /lib/tls.disable" procedure http://lists.xensource.com/archives/html/xen-users/2007-03/msg00424.html Unfortunately, I''ve tested all of them but no one solves the problem :( I would like to know about any other possible solution or any further info/pointer that could help me to debug and solve the problem, please. My distribution is Debian testing. A list of relevant Xen-related packages follows (it you need to know any other information regarding my system, don''t hesitate to ask it). host:~# dpkg -l | grep xen | cut -c 1-56 | grep ii ii libc6-xen 2.3.6.ds1-13 ii linux-image-2.6-xen-686 2.6.18+6 ii linux-image-2.6.18-4-xen-686 2.6.18.dfsg.1-11 ii linux-image-xen-686 2.6.18+6 ii linux-modules-2.6.18-4-xen-686 2.6.18.dfsg.1-11 ii xen-hypervisor-3.0.3-1-i386-pae 3.0.3-0-2 ii xen-tools 2.8-2 ii xen-utils-3.0.3-1 3.0.3-0-2 ii xen-utils-common 3.0.3-0-2 Thanks in advance! Best regards, -------------------- Fermín Galán Márquez CTTC - Centre Tecnològic de Telecomunicacions de Catalunya Parc Mediterrani de la Tecnologia, Av. del Canal Olímpic s/n, 08860 Castelldefels, Spain Room 1.02 Tel : +34 93 645 29 12 Fax : +34 93 645 29 01 Email address: fermin dot galan at cttc dot es _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Andy Smith
2007-Apr-17 21:16 UTC
Re: [Xen-users] 4gb seg fixup errors in Debian (usual hints don''t seem to work)
On Tue, Apr 17, 2007 at 01:34:20PM +0200, Fermín Galán Márquez wrote:> 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc5f0[...]> host:~# dpkg -l | grep xen | cut -c 1-56 | grep ii > ii libc6-xen 2.3.6.ds1-13Have you rebooted since you installed libc6-xen? Installing libc6-xen fixes this for me on Debian Etch, on several machines. But any binaries you had running from before you installed libc6-xen will be still using the old TLS libs until you restart them (or reboot). Bear in mind also that init (pid 1) will be statically linked against the old libs so you will always see warnings for that one process. Cheers, Andy _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fermín Galán Márquez
2007-Apr-18 15:50 UTC
RE: [Xen-users] 4gb seg fixup errors in Debian (usual hints don''tseem to work)
Dear Andy,>> 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc5f0 > > [...] > >> host:~# dpkg -l | grep xen | cut -c 1-56 | grep ii >> ii libc6-xen 2.3.6.ds1-13 > > Have you rebooted since you installed libc6-xen? Installing > libc6-xen fixes this for me on Debian Etch, on several machines. > But any binaries you had running from before you installed libc6-xen > will be still using the old TLS libs until you restart them (or > reboot).I''ve rebooted, but I''m still getting "4gb seg fixup" messages in the domU (note not only for init, but also for klogd, syslogd, bash, etc.): ... Apr 18 17:35:44 occ0-v kernel: 4gb seg fixup, process init (pid 1), cs:ip 73:b7dbdf16 Apr 18 17:35:44 occ0-v kernel: 4gb seg fixup, process init (pid 1), cs:ip 73:b7dfaccc Apr 18 17:35:44 occ0-v kernel: 4gb seg fixup, process sh (pid 987), cs:ip 73:b7e1cde1 Apr 18 17:35:49 occ0-v kernel: 4gb seg fixup, process S80local (pid 1088), cs:ip 73:b7e4a908 Apr 18 17:35:54 occ0-v kernel: 4gb seg fixup, process klogd (pid 1046), cs:ip 73:b7e356a0 Apr 18 17:36:13 occ0-v kernel: 4gb seg fixup, process syslogd (pid 1040), cs:ip 73:b7ead6d0 Apr 18 17:36:13 occ0-v kernel: 4gb seg fixup, process syslogd (pid 1040), cs:ip 73:b7ead650 Apr 18 17:36:13 occ0-v kernel: 4gb seg fixup, process klogd (pid 1046), cs:ip 73:b7e356a0 Apr 18 17:36:13 occ0-v kernel: 4gb seg fixup, process klogd (pid 1046), cs:ip 73:b7eb6dd0 Apr 18 17:36:21 occ0-v kernel: 4gb seg fixup, process getty (pid 1136), cs:ip 73:b7f0cccc Apr 18 17:36:25 occ0-v kernel: 4gb seg fixup, process login (pid 1136), cs:ip 73:b7e4e0a4 Apr 18 17:36:29 occ0-v kernel: 4gb seg fixup, process bash (pid 1142), cs:ip 73:b7de12a5 Apr 18 17:36:33 occ0-v kernel: 4gb seg fixup, process bash (pid 1142), cs:ip 73:b7de12a5 ... If the problem is related with libc6-xen, do you thing installing a newer version of the package could solve the it? I''ve checked in http://packages.debian.org/libc6-xen that the unstable and experimental branch include a libc6-xen 2.5 version (currently one installed is 2.3.6), although installing things unstable/experimental is always dangerous...> Bear in mind also that init (pid 1) will be statically linked > against the old libs so you will always see warnings for that one > process.I''m not sure of understand that... Do you mean that even after disabling TLS and rebooting in the best case (e.g., with a proper libc6-xen installed) the warnings can not be avoided? In that case, is a limitation of Debian (so other distributions don''t suffer it) or all distributions gets warning for the init process? As a matter of fact, what I worry about is not the warning itself but the performance penalty it involves (as explained at http://wiki.xensource.com/xenwiki/XenFaq#head-e05786f1e0d6a833bc146a6096cab2 d96f2b30ae). Thanks you for your answer! Best regards, -------------------- Fermín Galán Márquez CTTC - Centre Tecnològic de Telecomunicacions de Catalunya Parc Mediterrani de la Tecnologia, Av. del Canal Olímpic s/n, 08860 Castelldefels, Spain Room 1.02 Tel : +34 93 645 29 12 Fax : +34 93 645 29 01 Email address: fermin dot galan at cttc dot es _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fermín Galán Márquez
2007-Apr-21 19:33 UTC
RE: [Xen-users] 4gb seg fixup errors in Debian (usual hints don''t seemto work)
Hello,> I''m getting a lot of "4gb seg fixup error" messages in the console of my > domU, that I would like to avoid (not only due to "aesthetic", it impacts > the performance, as explained at > http://wiki.xensource.com/xenwiki/XenFaq#head- > e05786f1e0d6a833bc146a6096cab2d96f2b30ae). E.g.: > > 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc5f0 > 4gb seg fixup, process syslogd (pid 1107), cs:ip 73:b7efc570 > 4gb seg fixup, process klogd (pid 1113), cs:ip 73:b7e2e5f0 > 4gb seg fixup, process klogd (pid 1113), cs:ip 73:b7eafd10 > printk: 38 messages suppressed. > 4gb seg fixup, process named (pid 1128), cs:ip 73:b7bc5c1cAfter a lot of painful debugging :), I think I finally have found the cause of the problem and the solution. The filesystem of domU virtual machines was using conventional libc6 (belonging to the libc6 Debian package): domU:~# ldd /sbin/init | grep libc.so.6 libc.so.6 => /lib/tls/libc.so.6 (0xb7e0f000) So, I installed the libc6-xen package in the domU filesystem, that uses an libc6 variant optimized for Xen. After that: domU:~# ldd /sbin/init | grep libc.so.6 libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7e36000) And now warning messages have stopped! In conclusion, my mistake was thinking that the libc6-xen package was only needed in the dom0 filesystem, while it is also needed in domU ones. I send this email, to avoid the same confusion in future users :) Best regards, -------------------- Fermín Galán Márquez CTTC - Centre Tecnològic de Telecomunicacions de Catalunya Parc Mediterrani de la Tecnologia, Av. del Canal Olímpic s/n, 08860 Castelldefels, Spain Room 1.02 Tel : +34 93 645 29 12 Fax : +34 93 645 29 01 Email address: fermin dot galan at cttc dot es _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users