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| author | Nick Piggin <nickpiggin@yahoo.com.au> | 2005-12-02 02:44:19 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-02 23:20:21 +0100 |
| commit | 2a298a35ebe060a6f2b06b20c2a34ea188ddfd37 (patch) | |
| tree | 226dd2569d657231a3c24d8228467a039ffc6681 /drivers/acpi/processor_idle.c | |
| parent | Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 (diff) | |
| download | linux-2a298a35ebe060a6f2b06b20c2a34ea188ddfd37.tar.xz linux-2a298a35ebe060a6f2b06b20c2a34ea188ddfd37.zip | |
[PATCH] Fix TIF_POLLING_NRFLAG in ACPI idle routines
Commit 64c7c8f88559624abdbe12b5da6502e8879f8d28 broke the ACPI C2 and C3
sleep states, because it left TIF_POLLING_NRFLAG active even though
those states do not actually poll the reschedule flag at all. As a
result, the CPU wouldn't get sent an IPI when it was to be woken up, and
would only notice that it had runnable processes on the next timer tick.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 83fd1b6c10c4..acd875e0caca 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -169,15 +169,11 @@ acpi_processor_power_activate(struct acpi_processor *pr, static void acpi_safe_halt(void) { - int polling = test_thread_flag(TIF_POLLING_NRFLAG); - if (polling) { - clear_thread_flag(TIF_POLLING_NRFLAG); - smp_mb__after_clear_bit(); - } + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb__after_clear_bit(); if (!need_resched()) safe_halt(); - if (polling) - set_thread_flag(TIF_POLLING_NRFLAG); + set_thread_flag(TIF_POLLING_NRFLAG); } static atomic_t c3_cpu_count; @@ -295,6 +291,15 @@ static void acpi_processor_idle(void) * ------ * Invoke the current Cx state to put the processor to sleep. */ + if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) { + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb__after_clear_bit(); + if (need_resched()) { + set_thread_flag(TIF_POLLING_NRFLAG); + return; + } + } + switch (cx->type) { case ACPI_STATE_C1: @@ -327,6 +332,7 @@ static void acpi_processor_idle(void) t2 = inl(acpi_fadt.xpm_tmr_blk.address); /* Re-enable interrupts */ local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); /* Compute time (ticks) that we were actually asleep */ sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; @@ -366,6 +372,7 @@ static void acpi_processor_idle(void) /* Re-enable interrupts */ local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); /* Compute time (ticks) that we were actually asleep */ sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; |