Red Hat Bugzilla – Bug 440281
NR_CPUS limit of 8 reached
Last modified: 2012-06-20 12:09:28 EDT
Description of problem: I just purchased a Dell R900 server and installed Red Hat Linux Enterprise 4.6 (EMT64T) and updated the kernel to 2.6.9-67.0.7.ELsmp x86_64 version. This server has 4 quad-core processors (E7320). When I boot the system, it shows that I have 8 processors of the 16 processors running. In /var/log/messages in the boot process descriptions, I see the message "WARNING: NR_CPUS limit of 8 reached. Processor ignored." while the processors are being configured. Why is this version limiting the number of processors to 8 and how do I get all 16 processors operating? Version-Release number of selected component (if applicable): Red Hat Enterprise Linux AS, Release 4 update 6 2.6.9-67.0.7.ELsmp #1 SMP Wed Feb 27 04:47:23 EST 2008 x86_64 x86_64 x86_64 GNU/Linux How reproducible: Every time the system is booted up Steps to Reproduce: 1. Simply boot the system 2. 3. Actual results: limit of 8 processors Expected results: all 16 processors should be active Additional info:
Created attachment 300090 [details] output in messages file limiting to 8 processors
You need to run the largesmp kernel for systems with > 8 cpus on x86_64 in RHEL 4, (install kernel-largesmp-2.6.9-67.EL.x86_64.rpm). The largesmp x86_64 kernel supports up to 64 cpus. Install the largesmp kernel and you will see all 16 cpus.
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