Date: Sun, 08 Jul 2012 13:39:19 +0300 From: Andriy Gapon <avg@FreeBSD.org> To: "freebsd-acpi@freebsd.org" <freebsd-acpi@FreeBSD.org> Subject: safe acpi_cpu_idle disabling Message-ID: <4FF96357.1030601@FreeBSD.org>
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I would like to propose the following patch for your review: http://people.freebsd.org/~avg/acpi_cpu_disable_idle.diff The main purpose of this change is to provide safe interaction between acpi_cpu_idle and dynamic C-state changes by disabling acpi_cpu_idle while C-state data is updated. If my understanding is correct, currently there is no mutual protection between acpi_cpu_idle code and acpi_cpu_cx_cst. The code more or less works by never cleaning up old C-state data, so it is still accessible while the two functions have incoherent views. There still could be problems when acpi_cpu_idle expects C-state data at certain index to belong to one type while acpi_cpu_cx_cst changes it to a different type. P.S. I think that cpu_disable_idle should be made per-CPU (go to acpi_cpu softc). -- Andriy Gapon
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