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commit 7592019634f8473f0b0973ce79297183077bdbc2 upstream. According to current code implementation, detecting the long idle period is done by checking if the interval between two adjacent utilization update handlers is long enough. Although this mechanism can detect if the idle period is long enough (no utilization hooks invoked during idle period), it might not cover a corner case: if the task has occupied the CPU for too long which causes no context switches during that period, then no utilization handler will be launched until this high prio task is scheduled out. As a result, the idle_periods field might be calculated incorrectly because it regards the 100% load as 0% and makes the conservative governor who uses this field confusing. Change the detection to compare the idle_time with sampling_rate directly. Reported-by: Artem S. Tashkinov <t.artem@mailcity.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.