Latest FC kernel still have SMP bugs?
Nigel Wade
nmw at ion.le.ac.uk
Wed Apr 7 10:04:35 UTC 2004
Norman Gaywood wrote:
> 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 at ion.le.ac.uk
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555
More information about the fedora-list
mailing list