Hi,I was trying to do some experiments tounderstand the effect of hardware prefetcher on software prefetching.
I had a question related to h/w prefetcher on Intel Xeon processor,and was wondering if any of you have some suggestions.
My machine configuration:
$ uname -a
Linux 2.6.34-gentoo-r1 #2 SMP Mon Feb 20 12:07:35 CST 2012 x86_64
Intel Xeon CPU E5520 @ 2.27GHz GenuineIntel GNU/Linux
I am trying to count the number of hardware prefetch events (a.k.a.L1D_PREFETCH:REQUESTS perfmon2 event), before and after disablinghardware prefetching using BIOS. I have followed the steps mentionedin the below link to disable h/w prefetching in BIOS.
However even after disabling the h/w prefetching, I don't see it ishaving any effect on prefetching event L1D_PREFETCH:REQUESTS. I hadposted this query on perfmon2 group, and I was told that since theprocessor E5520 is not a Core micro-architecture but Nehalem-EP thetechnique above to disable HW prefetcher does not apply.
Do any of you have any suggestions about how we can disable h/w prefetcher on this architecture?