linux/arch/s390/include/asm/hiperdispatch.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright IBM Corp. 2024
 */

#ifndef _ASM_HIPERDISPATCH_H
#define _ASM_HIPERDISPATCH_H

void hd_reset_state(void);
void hd_add_core(int cpu);
void hd_disable_hiperdispatch(void);
int hd_enable_hiperdispatch(void);

#endif /* _ASM_HIPERDISPATCH_H */
s390/hiperdispatch: Introduce hiperdispatch When LPAR is in vertical polarization, CPUs get different polarization values, namely vertical high, vertical medium and vertical low. These values represent the likelyhood of the CPU getting physical runtime. Vertical high CPUs will always get runtime and others get varying runtime depending on the load the CEC is under. Vertical high and vertical medium CPUs are considered the CPUs which the current LPAR has the entitlement to run on. The vertical lows are on the other hand are borrowed CPUs which would only be given to the LPAR by hipervisor when the other LPARs are not utilizing them. Using the CPU capacities, hint linux scheduler when it should prioritise vertical high and vertical medium CPUs over vertical low CPUs. By tracking various system statistics hiperdispatch determines when to adjust cpu capacities. After each adjustment, rebuilding of scheduler domains is necessary to notify the scheduler about capacity changes but since this operation is costly it should be done as sparsely as possible. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Co-developed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 2024-08-12 13:39:34 +02:00			`/* SPDX-License-Identifier: GPL-2.0 */`
			`/*`
			`* Copyright IBM Corp. 2024`
			`*/`

			`#ifndef _ASM_HIPERDISPATCH_H`
			`#define _ASM_HIPERDISPATCH_H`

			`void hd_reset_state(void);`
			`void hd_add_core(int cpu);`
			`void hd_disable_hiperdispatch(void);`
			`int hd_enable_hiperdispatch(void);`

			`#endif /* _ASM_HIPERDISPATCH_H */`