This patch series removes cputime scaling from kernel. It can be easily done in user space using floating point if we provide sum_exec_runtime, what patches 2/4 and 3/4 do. I have procps patch which utilize that:
http://people.redhat.com/sgruszka/procps-use-sum_exec_runtime.patch I will post it, if this patch set will be queued. Change affect also getrusage() and times() syscals, but I don't think kernel give guarantees about utime/stime precision, in a matter of fact before commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa, we do not perform any scaling and we provided raw cputime values to user space. Providing sum_exec_runtime via proc is done against malware that utilize lot of cpu time but hide itself from top program. This affect kernels not compiled with CONFIG_VIRT_CPU_ACCOUNTING_{GEN,NATIVE}, if user choose to compile kernel with some of those options, he/she will have more precise cputime accounting, what is documented in Kconfig. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/