lowlevel.hpp

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/**
 * @file
 * @ingroup numapp_ll
 * @copyright ESO 2024 - European Southern Observatory
 *
 * @brief Contains low-level functions
 */
#ifndef NUMAPP_LOWLEVEL_HPP_
#define NUMAPP_LOWLEVEL_HPP_
#include "config.hpp"
 
#include <sched.h>
#include <system_error>
#include <variant>
 
#include "cpumask.hpp"
#include "nodemask.hpp"
 
namespace numapp {
/**
 * @brief Defines lowlevel functions that should not be used directly.
 * @ingroup numapp_ll
 */
namespace ll {
/**
 * A low-level, and error prone function to set policy.
 *
 * Prefer to use the @ref numapp::Apply() functions  instead.
 *
 * @ingroup numapp_ll
 */
std::error_code
SetSchedulerPolicy(pid_t pid, int policy, int static_priority, int dynamic_priority) NUMAPP_NOEXCEPT;
 
/**
 * A low-level, and error prone function to get policy.
 *
 * Prefer to use the @c numapp::Scheduler instead.
 *
 * @ingroup numapp_ll
 */
std::error_code
GetSchedulerPolicy(pid_t pid, int* policy, int* static_priority, int* dynamic_priority) NUMAPP_NOEXCEPT;
 
/**
 * Get CPU affinity.
 *
 * @param ttid Thread id to get the affinity from.
 * @param[out] mask
 * @return error code.
 *
 * @manpages
 * @manpage{numa,3}
 *
 * @ingroup numapp_ll
 */
std::error_code GetCpuAffinity(pid_t ttid, Cpumask& mask) NUMAPP_NOEXCEPT;
 
/**
 * Set CPU affinity.
 *
 * @param ttid Thread id to apply the affinity to.
 * @param mask CPU mask describing the desired affinity.
 * @return error code.
 *
 * @manpages
 * @manpage{numa,3}
 *
 * @ingroup numapp_ll
 */
std::error_code SetCpuAffinity(pid_t ttid, Cpumask const& mask) NUMAPP_NOEXCEPT;
 
 
/**
 * Convert NUMA node number to corresponding CPU mask.
 *
 * @param node NUMA node number to get mask for.
 * @param [out] mask Destination CPU mask.
 *
 * @ingroup numapp_ll
 */
std::error_code NumaNodeToCpumask(int node, Cpumask& mask) NUMAPP_NOEXCEPT;
 
 
/**
 * Get memory policy for calling thread or an address.
 *
 * See manpage for details.
 *
 * @manpages
 * @manpage{get_mempolicy,2}
 *
 * @param [out] mode memory policy.
 * @param [out] mask The output nodemask.
 * @param [in] addr Address to get policy for.
 * @param [in] flags Determines operation.
 * @return errors from get_mempolicy.
 *
 * @ingroup numapp_ll
 */
std::error_code GetMemPolicy(int& mode, Nodemask& mask, void* addr, unsigned flags) NUMAPP_NOEXCEPT;
 
/**
 * Set active memory policy for calling thread.
 *
 * @param mode memory policy.
 * @param mask the input nodemask.
 * @return errors from get_mempolicy.
 *
 * @ingroup numapp_ll
 */
std::error_code SetMemPolicy(int mode, Nodemask const& mask) NUMAPP_NOEXCEPT;
 
/**
 * Set memory policy for memory range.
 *
 * @param addr starting address.
 * @param len memory range length.
 * @param mode memory policy.
 * @param mask the input nodemask.
 * @param flags combination of MPOL_MF_* flags
 * @return errors from mbind.
 *
 * @ingroup numapp_ll
 */
std::error_code
SetMemPolicy(void* addr, std::size_t len, int mode, Nodemask const& mask, unsigned flags)
    NUMAPP_NOEXCEPT;
 
} // namespace ll
 
}  // namespace numapp
 
#endif