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author | Joao Martins <joao.m.martins@oracle.com> | 2019-09-08 02:45:21 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-09-11 18:36:30 +0300 |
commit | cb5d8c45ab6c3daf8269e550cfb2d5018a876fe3 (patch) | |
tree | 0d045a3cc65bd198bf7f139a550005a96b1ef4a5 /drivers/cpuidle/driver.c | |
parent | cd4c0763064f02f42824eed61be38eafdc702281 (diff) | |
download | linux-cb5d8c45ab6c3daf8269e550cfb2d5018a876fe3.tar.xz |
cpuidle: allow governor switch on cpuidle_register_driver()
The recently introduced haltpoll driver is largely only useful with
haltpoll governor. To allow drivers to associate with a particular idle
behaviour, add a @governor property to 'struct cpuidle_driver' and thus
allow a cpuidle driver to switch to a *preferred* governor on idle driver
registration. We save the previous governor, and when an idle driver is
unregistered we switch back to that.
The @governor can be overridden by cpuidle.governor= boot param or
alternatively be ignored if the governor doesn't exist.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle/driver.c')
-rw-r--r-- | drivers/cpuidle/driver.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index dc32f34e68d9..80c1a830d991 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -254,12 +254,25 @@ static void __cpuidle_unregister_driver(struct cpuidle_driver *drv) */ int cpuidle_register_driver(struct cpuidle_driver *drv) { + struct cpuidle_governor *gov; int ret; spin_lock(&cpuidle_driver_lock); ret = __cpuidle_register_driver(drv); spin_unlock(&cpuidle_driver_lock); + if (!ret && !strlen(param_governor) && drv->governor && + (cpuidle_get_driver() == drv)) { + mutex_lock(&cpuidle_lock); + gov = cpuidle_find_governor(drv->governor); + if (gov) { + cpuidle_prev_governor = cpuidle_curr_governor; + if (cpuidle_switch_governor(gov) < 0) + cpuidle_prev_governor = NULL; + } + mutex_unlock(&cpuidle_lock); + } + return ret; } EXPORT_SYMBOL_GPL(cpuidle_register_driver); @@ -274,9 +287,21 @@ EXPORT_SYMBOL_GPL(cpuidle_register_driver); */ void cpuidle_unregister_driver(struct cpuidle_driver *drv) { + bool enabled = (cpuidle_get_driver() == drv); + spin_lock(&cpuidle_driver_lock); __cpuidle_unregister_driver(drv); spin_unlock(&cpuidle_driver_lock); + + if (!enabled) + return; + + mutex_lock(&cpuidle_lock); + if (cpuidle_prev_governor) { + if (!cpuidle_switch_governor(cpuidle_prev_governor)) + cpuidle_prev_governor = NULL; + } + mutex_unlock(&cpuidle_lock); } EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); |