![]() The related Red Hat Private Bug is 1001954. This package is available via Errata RHSA-2013:1436. The related Red Hat Private Bug is 975507. This package is available via Errata RHSA-2013:1645. This issue is addressed in the following kernel updates: This is documented in the Intel® Xeon® E7-2800/4800/8800 v2 Product Family Specification Update as erratum CF101. On Intel® Xeon® Processor E7 v2 Family 6 Model 62 (also known as IvyBridge-EX), the Time Stamp Counter (TSC) is not cleared by a warm reset. This is documented in the Intel® Xeon® Processor E5 v2 Family Specification Update as erratum CA105. On Intel® Xeon® Processor E5 v2 Family 6 Model 62 (also known as IvyBridge), the Time Stamp Counter (TSC) is not cleared by a warm reset. This is documented in the Intel® Xeon® Processor E5 Family Specification Update as erratum BT81. On Intel® Xeon® Processor E5 Family 6 Model 45 (also known as SandyBridge), the Time Stamp Counter (TSC) is not cleared by a warm reset. ![]() Systems with Intel® Xeon® Processor E5, Intel® Xeon® Processor E5 v2, or Intel® Xeon® Processor E7 v2 and certain versions of Red Hat Enterprise Linux 6 kernels become unresponsive/hung or incur a kernel panic Version: Intel(R) Xeon(R) CPU E5-2643 v2 3.50GHzĭescription: Red Hat Enterprise Linux Server release 6.4 (Santiago) When I now sum up the values for all processes and compare it to the overall calculated CPU usage, I receive a slightly higher value for the aggregated value most of the time (although the values are quite close for all different CPU loads).Ĭan anyone explain to me, what's the reason for that? Are there any CPU resources that are used by more than one process and thus accounted twice or more in my accumlation? Or am I simply missing something here? I can not find any further hint in the Linux man page for the proc file system ( ) as well.- ps 명령으로 프로세스 정보 조회 시 utime과 stime이 크게 확인됨 (리부팅 후에도 동일) When I now calculate this sum and divide it by the total amount of jiffies in the analyzed interval, I would assume the formula for one process to be processCPUUsage = ((process_utime_aft - process_utime_bef) + (process_stime_aft - process_stime_bef)) / ![]() ((user_aft - user_bef) + (nice_aft - nice_bef) + (system_aft - system_bef) + (idle_aft - idle_bef)) * 100 %Īccording to How to calculate the CPU usage of a process by PID in Linux from C? the used jiffies for a single process can be calculated by adding utime and stime from /proc/$/stat (column 14 and 15 in this file). The formula would be totalCPUUsage = ((user_aft - user_bef) + (nice_aft - nice_bef) + (system_aft - system_bef)) / If you now sample the values at two points in time and compare the values for user, nice, system and idle at the two time points, you can calculate the average CPU usage in this interval. For now the CPU I am using is multi-cored (2 cores).Īccording to How to determine CPU and memory consumption from inside a process? it is possible to calculate all "jiffies" available in the system since startup using the values for "cpu" in /proc/stat. My assumption would be that the sum of all process CPU times would be equal to the total value for the whole CPU. The programm should be designed and implemented in C++. I need to calculate the overall CPU usage of my Linux device over some time (1-5 seconds) and a list of processes with their respective CPU usage times. ![]()
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