On Tue, Apr 06, 2004 at 03:38:21PM +0100, Nigel Wade wrote:
Nigel Wade wrote:
Norman Gaywood wrote:
On Fri, Apr 02, 2004 at 11:31:06AM +0100, Nigel Wade wrote:
Unfortunately, RH9/RHEL3 don't have the version of LDAP I require, and when I tried an upgrade to openldap I started getting FUTEX locking problems.
Install the RHEL3 kernel on FC1. I installed:
kernel-smp-2.4.21-9.0.1.EL kernel-smp-unsupported-2.4.21-9.0.1.EL
Ok, the bottom line is that this doesn't work either.
I've built the RHEL3 kernel on FC1 and run the system up using this. Ordinary ldap requests seem quite happy, but I'm still seeing the futex lock problem with nss_ldap. E.g. when I add 'hosts: files ldap dns' to /etc/nsswitch.conf I get:
# strace ping host munmap(0xb75ff000, 4096) = 0 uname({sys="Linux", node="hostname", ...}) = 0 futex(0x53e4ec, FUTEX_WAIT, 2, NULL
Interesting. I thought the EL kernel had the fast futex code back-ported but I have not checked this. So I thought the EL kernel would work like RH9 and FC1 kernels.
I've since found a bug listed in bugzilla specifically related to ping and futex - https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=110563
The workaround there is to build nss_ldap from PADL rather than use the FC1 version. That will be my next step.
Could I ask what what steps you took to build the EL kernel on FC1? I didn't have much luck building with rpmbuild when I tried this.
I built the kernel RPMs from src.rpm on a RH9 system, I couldn't get them to build on FC1. I then installed the kernel-source RPM on the FC1 system. After the ususal 'make mproper; cp configs/whatever .config; make oldconfig; make xconfig' I edited the Makefile and set it to use gcc32 rather than gcc. Then 'make dep; make bzImage; make modules; make modules_install; make install'. The reboot with the new kernel.
Setting LD_ASSUME_KERNEL=2.4.1 cures this particular problem, but isn't a solution for a system relying on LDAP for all authentication and NSS functions.
Another suggestion for you to try is on one of the bugzillas. That is, to rebuild the FC1 kernel with low latency scheduling turned off. Maybe that's your best option.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=109962
Comments #42 and #44
Ok, that's new since I last looked. I'll give it a go and see what happens.
-- Nigel Wade, System Administrator, Space Plasma Physics Group, University of Leicester, Leicester, LE1 7RH, UK E-mail : nmw@xxxxxxxxxxxx Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555
