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realtime:documentation:howto:tools:perf-smi-cost [2018/07/13 10:57] ebugden Make todo more gently phrased |
realtime:documentation:howto:tools:perf-smi-cost [2018/07/13 11:02] ebugden Remove s in SMIs from link |
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====== Perf stat - SMI cost ====== | ====== Perf stat - SMI cost ====== | ||
- | Perf's stat tool has an option that can measure the cost of SMIs (--smi-cost) if the necessary MSRs exist on the CPU. This option calculates the percentage of cycles spent handling SMIs. If the --no-metric-only option is also used, the tool can be used to determine the average number of cycles taken to handle an SMI during the measurement period. These Perf options are available as of the 4.13 linux kernel and will only work on Intel x86 processors from after around 2008 (as of the Nehalem microarchitecture). | + | Perf's stat tool has an option that can measure the cost of [[realtime:documentation:howto:debugging:smi-latency:start|SMI]]s (--smi-cost) if the necessary MSRs exist on the CPU. This option calculates the percentage of cycles spent handling SMIs. If the --no-metric-only option is also used, the tool can be used to determine the average number of cycles taken to handle an SMI during the measurement period. These Perf options are available as of the 4.13 linux kernel and will only work on Intel x86 processors from after around 2008 (as of the Nehalem microarchitecture). |
===== Installation ===== | ===== Installation ===== |