Date: Sat, 1 Dec 2012 18:06:05 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r243761 - head/sys/dev/acpica Message-ID: <201212011806.qB1I65EM062470@svn.freebsd.org>
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Author: avg Date: Sat Dec 1 18:06:05 2012 New Revision: 243761 URL: http://svnweb.freebsd.org/changeset/base/243761 Log: acpi_cpu_notify: disable acpi_cpu_idle while updating C-state data ... to avoid any races or inconsistencies. This should fix a regression introduced in r243404. Also, remove a stale comment that has not been true for quite a while now. Pointyhat to: avg Teested by: trociny, emaste, dumbbell (earlier version) MFC after: 1 week Modified: head/sys/dev/acpica/acpi_cpu.c Modified: head/sys/dev/acpica/acpi_cpu.c ============================================================================== --- head/sys/dev/acpica/acpi_cpu.c Sat Dec 1 18:01:01 2012 (r243760) +++ head/sys/dev/acpica/acpi_cpu.c Sat Dec 1 18:06:05 2012 (r243761) @@ -973,9 +973,9 @@ acpi_cpu_idle() return; } - /* If disabled, return immediately. */ + /* If disabled, take the safe path. */ if (is_idle_disabled(sc)) { - ACPI_ENABLE_IRQS(); + acpi_cpu_c1(); return; } @@ -1081,23 +1081,31 @@ acpi_cpu_idle() /* * Re-evaluate the _CST object when we are notified that it changed. - * - * XXX Re-evaluation disabled until locking is done. */ static void acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context) { struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context; - + if (notify != ACPI_NOTIFY_CX_STATES) return; + /* + * C-state data for target CPU is going to be in flux while we execute + * acpi_cpu_cx_cst, so disable entering acpi_cpu_idle. + * Also, it may happen that multiple ACPI taskqueues may concurrently + * execute notifications for the same CPU. ACPI_SERIAL is used to + * protect against that. + */ + ACPI_SERIAL_BEGIN(cpu); + disable_idle(sc); + /* Update the list of Cx states. */ acpi_cpu_cx_cst(sc); acpi_cpu_cx_list(sc); - - ACPI_SERIAL_BEGIN(cpu); acpi_cpu_set_cx_lowest(sc); + + enable_idle(sc); ACPI_SERIAL_END(cpu); acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);
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