[1/4] power: fix non thread-safe power env modification
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Commit Message
From: Marcin Hajkowski <marcinx.hajkowski@intel.com>
Due to lack of thread safety in exisiting solution
use spinlock mechanism for atomic
modification of power environment related data.
Fixes: 445c6528b5 ("power: common interface for guest and host")
Cc: stable@dpdk.org
Signed-off-by: Marcin Hajkowski <marcinx.hajkowski@intel.com>
---
doc/guides/rel_notes/release_19_05.rst | 2 ++
lib/librte_power/rte_power.c | 30 ++++++++++++++++++--------
lib/librte_power/rte_power.h | 2 +-
3 files changed, 24 insertions(+), 10 deletions(-)
@@ -120,6 +120,8 @@ API Changes
Also, make sure to start the actual text at the margin.
=========================================================
+ * power: ``rte_power_set_env`` and ``rte_power_unset_env`` functions
+ have been modified to be thread safe.
ABI Changes
-----------
@@ -2,7 +2,7 @@
* Copyright(c) 2010-2014 Intel Corporation
*/
-#include <rte_atomic.h>
+#include <rte_spinlock.h>
#include "rte_power.h"
#include "power_acpi_cpufreq.h"
@@ -12,7 +12,7 @@
enum power_management_env global_default_env = PM_ENV_NOT_SET;
-volatile uint32_t global_env_cfg_status = 0;
+static rte_spinlock_t global_env_cfg_lock = RTE_SPINLOCK_INITIALIZER;
/* function pointers */
rte_power_freqs_t rte_power_freqs = NULL;
@@ -30,9 +30,15 @@ rte_power_get_capabilities_t rte_power_get_capabilities;
int
rte_power_set_env(enum power_management_env env)
{
- if (rte_atomic32_cmpset(&global_env_cfg_status, 0, 1) == 0) {
+ rte_spinlock_lock(&global_env_cfg_lock);
+
+ if (global_default_env != PM_ENV_NOT_SET) {
+ rte_spinlock_unlock(&global_env_cfg_lock);
return 0;
}
+
+ int ret = 0;
+
if (env == PM_ENV_ACPI_CPUFREQ) {
rte_power_freqs = power_acpi_cpufreq_freqs;
rte_power_get_freq = power_acpi_cpufreq_get_freq;
@@ -73,18 +79,24 @@ rte_power_set_env(enum power_management_env env)
} else {
RTE_LOG(ERR, POWER, "Invalid Power Management Environment(%d) set\n",
env);
- rte_power_unset_env();
- return -1;
+ ret = -1;
}
- global_default_env = env;
- return 0;
+
+ if (ret == 0)
+ global_default_env = env;
+ else
+ global_default_env = PM_ENV_NOT_SET;
+
+ rte_spinlock_unlock(&global_env_cfg_lock);
+ return ret;
}
void
rte_power_unset_env(void)
{
- if (rte_atomic32_cmpset(&global_env_cfg_status, 1, 0) != 0)
- global_default_env = PM_ENV_NOT_SET;
+ rte_spinlock_lock(&global_env_cfg_lock);
+ global_default_env = PM_ENV_NOT_SET;
+ rte_spinlock_unlock(&global_env_cfg_lock);
}
enum power_management_env
@@ -26,7 +26,7 @@ enum power_management_env {PM_ENV_NOT_SET, PM_ENV_ACPI_CPUFREQ, PM_ENV_KVM_VM,
/**
* Set the default power management implementation. If this is not called prior
* to rte_power_init(), then auto-detect of the environment will take place.
- * It is not thread safe.
+ * It is thread safe.
*
* @param env
* env. The environment in which to initialise Power Management for.