how to get event of UNC_DRAM_PAGE_CLOSE.CHO

how to get event of UNC_DRAM_PAGE_CLOSE.CHO

Hello,

I'm trying to get event UNC_DRAM_PAGE_CLOSE.CHO, but I always get 0. I use perf, and my OS is ubunto. My server is Intel xeon E5620.

I can get  UNC_DRAM_OPEN.CHO, But I can't get  UNC_DRAM_PAGE_CLOSE.CHO.

Do any body come across this question?

thanks a lot

lin wang

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Roman Dementiev (Intel)'s picture

Hi Lin Wang,

on the screen shot I see that only the count for raw event 0x461 is zero. Event 0x461 is UNC_DRAM_PAGE_CLOSE.CH2 and not UNC_DRAM_PAGE_CLOSE.CH0. Instead you have to use event 0x161 to monitor UNC_DRAM_PAGE_CLOSE.CH0.

Best regards,
Roman

Hello Roman Dementiev,
Thanks for your reply, I upload a new screen shot. I can't get 0x161,0x261,0x461,0x162,0x262,0x462.
I can get dram open event, but i can't get dram page close event and dram page miss event.
I don't know why?
best regards,
lin wang

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John D. McCalpin's picture

I had no trouble reading these events on my Intel Xeon X5680 using utilities from msrtools-1.2 to read and write the uncore performance monitor MSRs. I did not think that "perf" had any provisions for accessing the MSR-based uncore counters?

John D. McCalpin, PhD "Dr. Bandwidth"
Roman Dementiev (Intel)'s picture

Hi Lin Wang,

what is the version of Linux kernel are you using? Could you post the complete command line for perf that you are using with the raw events ?

Best regards,
Roman

Hello Roman Dementiev,
I attach two screen shot for my linux kernel and command line.
best regards.
lin wang

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hello,jdmccalpin,
Use 'perf list --help',show like screen shot, perf can access raw event.

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Download perf-raw-event.jpg141.34 KB
Roman Dementiev (Intel)'s picture

Hi Lin Wang,

the -e rXXX format is to collect statistics for *on-core* raw PMU events.But you would like to monitor events from *uncore* PMU. I need to check on the status of perf uncore support in Linux. There was a recent development in that direction. In the meantime, could you send the Linux kernel version you are using ("uname -a" command).

Roman

Roman Dementiev (Intel)'s picture

The initial support for Xeon E5620 (and other processors with microarchitecture codenamed Nehalem-EP, Westmere-EP and SandyBridge-EP) uncore events is included into the Linux kernel mainline starting from version 3.5

hello Roman
this screen shot is my linux kernel
best regards,
lin wang

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Roman Dementiev (Intel)'s picture
Best Reply

Hi Lin Wang,

the uncore PMU is not supported in perf in your Linux kernel. You need to try Linux kernel 3.5.

Thanks,
Roman

hello, Roman,
where are you find information about the support linux version, can you give me the link or document. I want learn more. Thank you.
best regards,
lin wang

Roman Dementiev (Intel)'s picture

Hi Lin Wang,

the uncore perf support has been improved in Linux kernel 3.6: see here .

Roman

I have installed linux-tools-3.5 for profiling,but I can't get uncore PMU now, I will try linux-tools-3.6 the next few days.

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