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[Xen-devel] [PATCH][RFC][0/2] x86 SMP: enables core-pair topology detect

To: "'xen-devel@xxxxxxxxxxxxxxxxxxx'" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Keir Fraser <keir.xen@xxxxxxxxx>, <george.dunlap@xxxxxxxxxxxxx>, Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: [Xen-devel] [PATCH][RFC][0/2] x86 SMP: enables core-pair topology detection for AMD CPUs
From: Wei Huang <wei.huang2@xxxxxxx>
Date: Thu, 23 Jun 2011 17:51:50 -0500
Delivery-date: Thu, 23 Jun 2011 15:56:12 -0700
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The following two patches enable core-pair topology detection for AMD CPUs. The main idea is to record compute unit information into cpuinfo_x86 and use it when building sibling map. The sibling map will be used by Xen credit scheduler to coordinate VCPU scheduling in a fashion similar to SMT. This code is very similar to upstream Linux kernel.

Regarding the performance improvement, I saw ~8% improvement running kernel compilation on Dom0 with this patch. Anrea Przywara ran a POVRay benchmark using this patch and he saw ~5% improvement. No perf degradation was seen so far.

Please review.


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