Messages in this thread Patch in this message | | | Date | Fri, 25 Jul 2008 18:00:42 -0400 | From | Steven Rostedt <> | Subject | [PATCH 2/2] ftrace: disable tracing on acpi idle calls |
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The acpi idle waits calls local_irq_save and then uses mwait to go into idle. The tracer gets reenabled at local_irq_save but does not detect that the idle allows for wake ups.
This patch adds code to disable the tracing when acpi puts the CPU to idle.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Index: linux-tip.git/drivers/acpi/processor_idle.c =================================================================== --- linux-tip.git.orig/drivers/acpi/processor_idle.c +++ linux-tip.git/drivers/acpi/processor_idle.c @@ -272,6 +272,8 @@ static atomic_t c3_cpu_count; /* Common C-state entry for C2, C3, .. */ static void acpi_cstate_enter(struct acpi_processor_cx *cstate) { + /* Don't trace irqs off for idle */ + stop_critical_timings(); if (cstate->entry_method == ACPI_CSTATE_FFH) { /* Call into architectural FFH based C-state */ acpi_processor_ffh_cstate_enter(cstate); @@ -284,6 +286,7 @@ static void acpi_cstate_enter(struct acp gets asserted in time to freeze execution properly. */ unused = inl(acpi_gbl_FADT.xpm_timer_block.address); } + start_critical_timings(); } #endif /* !CONFIG_CPU_IDLE */ @@ -1418,6 +1421,8 @@ static inline void acpi_idle_update_bm_r */ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx) { + /* Don't trace irqs off for idle */ + stop_critical_timings(); if (cx->entry_method == ACPI_CSTATE_FFH) { /* Call into architectural FFH based C-state */ acpi_processor_ffh_cstate_enter(cx); @@ -1432,6 +1437,7 @@ static inline void acpi_idle_do_entry(st gets asserted in time to freeze execution properly. */ unused = inl(acpi_gbl_FADT.xpm_timer_block.address); } + start_critical_timings(); } /** --
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