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| author | Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> | 2015-06-18 13:23:11 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-06-22 15:15:15 +0200 |
| commit | 78eaa10f027cf69f9bd409e64eaff902172b2327 (patch) | |
| tree | cf3a819d4726147b8214eb4a6337b2423c1d245f /drivers/cpuidle/cpuidle-powernv.c | |
| parent | cpuidle: Do not use CPUIDLE_DRIVER_STATE_START in cpuidle.c (diff) | |
| download | linux-78eaa10f027cf69f9bd409e64eaff902172b2327.tar.xz linux-78eaa10f027cf69f9bd409e64eaff902172b2327.zip | |
cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state
The idle cpus which stay in snooze for a long period can degrade the
perfomance of the sibling cpus. If the cpu stays in snooze for more
than target residency of the next available idle state, then exit from
snooze. This gives a chance to the cpuidle governor to re-evaluate the
last idle state of the cpu to promote it to deeper idle states.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle/cpuidle-powernv.c')
| -rw-r--r-- | drivers/cpuidle/cpuidle-powernv.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 59372077ec7c..1e3ef5ec4784 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -29,18 +29,25 @@ struct cpuidle_driver powernv_idle_driver = { static int max_idle_state; static struct cpuidle_state *cpuidle_state_table; +static u64 snooze_timeout; +static bool snooze_timeout_en; static int snooze_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { + u64 snooze_exit_time; + local_irq_enable(); set_thread_flag(TIF_POLLING_NRFLAG); + snooze_exit_time = get_tb() + snooze_timeout; ppc64_runlatch_off(); while (!need_resched()) { HMT_low(); HMT_very_low(); + if (snooze_timeout_en && get_tb() > snooze_exit_time) + break; } HMT_medium(); @@ -252,6 +259,11 @@ static int powernv_idle_probe(void) cpuidle_state_table = powernv_states; /* Device tree can indicate more idle states */ max_idle_state = powernv_add_idle_states(); + if (max_idle_state > 1) { + snooze_timeout_en = true; + snooze_timeout = powernv_states[1].target_residency * + tb_ticks_per_usec; + } } else return -ENODEV; |