litmus-rt.git - The LITMUS^RT kernel.

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Diffstat (limited to 'drivers/message/fusion/mptdebug.h')

-rw-r--r--

288

1 files changed, 288 insertions, 0 deletions


diff --git a/drivers/message/fusion/mptdebug.h b/drivers/message/fusion/mptdebug.h new file mode 100644 index 000000000000..ffdb0a6191b4 --- /dev/null +++ b/drivers/message/fusion/mptdebug.h
@@ -0,0 +1,288 @@
	1	/*
	2	* linux/drivers/message/fusion/mptdebug.h
	3	* For use with LSI PCI chip/adapter(s)
	4	* running LSI Fusion MPT (Message Passing Technology) firmware.
	5	*
	6	* Copyright (c) 1999-2007 LSI Corporation
	7	* (mailto:DL-MPTFusionLinux@lsi.com)
	8	*
	9	*/
	10	/=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=/
	11
	12	#ifndef MPTDEBUG_H_INCLUDED
	13	#define MPTDEBUG_H_INCLUDED
	14
	15	/*
	16	* debug level can be programmed on the fly via SysFS (hex values)
	17	*
	18	* Example: (programming for MPT_DEBUG_EVENTS on host 5)
	19	*
	20	* echo 8 > /sys/class/scsi_host/host5/debug_level
	21	*
	22	* --------------------------------------------------------
	23	* mpt_debug_level - command line parameter
	24	* this allow enabling debug at driver load time (for all iocs)
	25	*
	26	* Example (programming for MPT_DEBUG_EVENTS)
	27	*
	28	* insmod mptbase.ko mpt_debug_level=8
	29	*
	30	* --------------------------------------------------------
	31	* CONFIG_FUSION_LOGGING - enables compiling debug into driver
	32	* this can be enabled in the driver Makefile
	33	*
	34	*
	35	* --------------------------------------------------------
	36	* Please note most debug prints are set to logging priority = debug
	37	* This is the lowest level, and most verbose. Please refer to manual
	38	* pages for syslogd or syslogd-ng on how to configure this.
	39	*/
	40
	41	#define MPT_DEBUG 0x00000001
	42	#define MPT_DEBUG_MSG_FRAME 0x00000002
	43	#define MPT_DEBUG_SG 0x00000004
	44	#define MPT_DEBUG_EVENTS 0x00000008
	45	#define MPT_DEBUG_VERBOSE_EVENTS 0x00000010
	46	#define MPT_DEBUG_INIT 0x00000020
	47	#define MPT_DEBUG_EXIT 0x00000040
	48	#define MPT_DEBUG_FAIL 0x00000080
	49	#define MPT_DEBUG_TM 0x00000100
	50	#define MPT_DEBUG_DV 0x00000200
	51	#define MPT_DEBUG_REPLY 0x00000400
	52	#define MPT_DEBUG_HANDSHAKE 0x00000800
	53	#define MPT_DEBUG_CONFIG 0x00001000
	54	#define MPT_DEBUG_DL 0x00002000
	55	#define MPT_DEBUG_RESET 0x00008000
	56	#define MPT_DEBUG_SCSI 0x00010000
	57	#define MPT_DEBUG_IOCTL 0x00020000
	58	#define MPT_DEBUG_FC 0x00080000
	59	#define MPT_DEBUG_SAS 0x00100000
	60	#define MPT_DEBUG_SAS_WIDE 0x00200000
	61
	62	/*
	63	* CONFIG_FUSION_LOGGING - enabled in Kconfig
	64	*/
	65
	66	#ifdef CONFIG_FUSION_LOGGING
	67	#define MPT_CHECK_LOGGING(IOC, CMD, BITS) \
	68	{ \
	69	if (IOC->debug_level & BITS) \
	70	CMD; \
	71	}
	72	#else
	73	#define MPT_CHECK_LOGGING(IOC, CMD, BITS)
	74	#endif
	75
	76
	77	/*
	78	* debug macros
	79	*/
	80
	81	#define dprintk(IOC, CMD) \
	82	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG)
	83
	84	#define dsgprintk(IOC, CMD) \
	85	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SG)
	86
	87	#define devtprintk(IOC, CMD) \
	88	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_EVENTS)
	89
	90	#define devtverboseprintk(IOC, CMD) \
	91	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_VERBOSE_EVENTS)
	92
	93	#define dinitprintk(IOC, CMD) \
	94	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_INIT)
	95
	96	#define dexitprintk(IOC, CMD) \
	97	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_EXIT)
	98
	99	#define dfailprintk(IOC, CMD) \
	100	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_FAIL)
	101
	102	#define dtmprintk(IOC, CMD) \
	103	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_TM)
	104
	105	#define ddvprintk(IOC, CMD) \
	106	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_DV)
	107
	108	#define dreplyprintk(IOC, CMD) \
	109	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_REPLY)
	110
	111	#define dhsprintk(IOC, CMD) \
	112	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_HANDSHAKE)
	113
	114	#define dcprintk(IOC, CMD) \
	115	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_CONFIG)
	116
	117	#define ddlprintk(IOC, CMD) \
	118	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_DL)
	119
	120	#define drsprintk(IOC, CMD) \
	121	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_RESET)
	122
	123	#define dsprintk(IOC, CMD) \
	124	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SCSI)
	125
	126	#define dctlprintk(IOC, CMD) \
	127	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_IOCTL)
	128
	129	#define dfcprintk(IOC, CMD) \
	130	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_FC)
	131
	132	#define dsasprintk(IOC, CMD) \
	133	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SAS)
	134
	135	#define dsaswideprintk(IOC, CMD) \
	136	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_SAS_WIDE)
	137
	138
	139
	140	/*
	141	* Verbose logging
	142	*/
	143	#if defined(MPT_DEBUG_VERBOSE) && defined(CONFIG_FUSION_LOGGING)
	144	static inline void
	145	DBG_DUMP_FW_DOWNLOAD(MPT_ADAPTER ioc, u32 mfp, int numfrags)
	146	{
	147	int i;
	148
	149	if (!(ioc->debug_level & MPT_DEBUG))
	150	return;
	151	printk(KERN_DEBUG "F/W download request:\n");
	152	for (i=0; i < 7+numfrags*2; i++)
	153	printk(" %08x", le32_to_cpu(mfp[i]));
	154	printk("\n");
	155	}
	156
	157	static inline void
	158	DBG_DUMP_PUT_MSG_FRAME(MPT_ADAPTER ioc, u32 mfp)
	159	{
	160	int ii, n;
	161
	162	if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME))
	163	return;
	164	printk(KERN_DEBUG "%s: About to Put msg frame @ %p:\n",
	165	ioc->name, mfp);
	166	n = ioc->req_sz/4 - 1;
	167	while (mfp[n] == 0)
	168	n--;
	169	for (ii=0; ii<=n; ii++) {
	170	if (ii && ((ii%8)==0))
	171	printk("\n");
	172	printk(" %08x", le32_to_cpu(mfp[ii]));
	173	}
	174	printk("\n");
	175	}
	176
	177	static inline void
	178	DBG_DUMP_FW_REQUEST_FRAME(MPT_ADAPTER ioc, u32 mfp)
	179	{
	180	int i, n;
	181
	182	if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME))
	183	return;
	184	n = 10;
	185	printk(KERN_INFO " ");
	186	for (i = 0; i < n; i++)
	187	printk(" %08x", le32_to_cpu(mfp[i]));
	188	printk("\n");
	189	}
	190
	191	static inline void
	192	DBG_DUMP_REQUEST_FRAME(MPT_ADAPTER ioc, u32 mfp)
	193	{
	194	int i, n;
	195
	196	if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME))
	197	return;
	198	n = 24;
	199	for (i=0; i<n; i++) {
	200	if (i && ((i%8)==0))
	201	printk("\n");
	202	printk("%08x ", le32_to_cpu(mfp[i]));
	203	}
	204	printk("\n");
	205	}
	206
	207	static inline void
	208	DBG_DUMP_REPLY_FRAME(MPT_ADAPTER ioc, u32 mfp)
	209	{
	210	int i, n;
	211
	212	if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME))
	213	return;
	214	n = (le32_to_cpu(mfp[0]) & 0x00FF0000) >> 16;
	215	printk(KERN_INFO " ");
	216	for (i=0; i<n; i++)
	217	printk(" %08x", le32_to_cpu(mfp[i]));
	218	printk("\n");
	219	}
	220
	221	static inline void
	222	DBG_DUMP_REQUEST_FRAME_HDR(MPT_ADAPTER ioc, u32 mfp)
	223	{
	224	int i, n;
	225
	226	if (!(ioc->debug_level & MPT_DEBUG_MSG_FRAME))
	227	return;
	228	n = 3;
	229	printk(KERN_INFO " ");
	230	for (i=0; i<n; i++)
	231	printk(" %08x", le32_to_cpu(mfp[i]));
	232	printk("\n");
	233	}
	234
	235	static inline void
	236	DBG_DUMP_TM_REQUEST_FRAME(MPT_ADAPTER ioc, u32 mfp)
	237	{
	238	int i, n;
	239
	240	if (!(ioc->debug_level & MPT_DEBUG_TM))
	241	return;
	242	n = 13;
	243	printk(KERN_DEBUG "TM_REQUEST:\n");
	244	for (i=0; i<n; i++) {
	245	if (i && ((i%8)==0))
	246	printk("\n");
	247	printk("%08x ", le32_to_cpu(mfp[i]));
	248	}
	249	printk("\n");
	250	}
	251
	252	static inline void
	253	DBG_DUMP_TM_REPLY_FRAME(MPT_ADAPTER ioc, u32 mfp)
	254	{
	255	int i, n;
	256
	257	if (!(ioc->debug_level & MPT_DEBUG_TM))
	258	return;
	259	n = (le32_to_cpu(mfp[0]) & 0x00FF0000) >> 16;
	260	printk(KERN_DEBUG "TM_REPLY MessageLength=%d:\n", n);
	261	for (i=0; i<n; i++) {
	262	if (i && ((i%8)==0))
	263	printk("\n");
	264	printk(" %08x", le32_to_cpu(mfp[i]));
	265	}
	266	printk("\n");
	267	}
	268
	269	#define dmfprintk(IOC, CMD) \
	270	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_MSG_FRAME)
	271
	272	# else /* ifdef MPT_DEBUG_MF */
	273
	274	#define DBG_DUMP_FW_DOWNLOAD(IOC, mfp, numfrags)
	275	#define DBG_DUMP_PUT_MSG_FRAME(IOC, mfp)
	276	#define DBG_DUMP_FW_REQUEST_FRAME(IOC, mfp)
	277	#define DBG_DUMP_REQUEST_FRAME(IOC, mfp)
	278	#define DBG_DUMP_REPLY_FRAME(IOC, mfp)
	279	#define DBG_DUMP_REQUEST_FRAME_HDR(IOC, mfp)
	280	#define DBG_DUMP_TM_REQUEST_FRAME(IOC, mfp)
	281	#define DBG_DUMP_TM_REPLY_FRAME(IOC, mfp)
	282
	283	#define dmfprintk(IOC, CMD) \
	284	MPT_CHECK_LOGGING(IOC, CMD, MPT_DEBUG_MSG_FRAME)
	285
	286	#endif /* defined(MPT_DEBUG_VERBOSE) && defined(CONFIG_FUSION_LOGGING) */
	287
	288	#endif /* ifndef MPTDEBUG_H_INCLUDED */

/* * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH) * * Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * * Interactivity improvements by Mike Galbraith * (C) 2007 Mike Galbraith <efault@gmx.de> * * Various enhancements by Dmitry Adamushko. * (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com> * * Group scheduling enhancements by Srivatsa Vaddagiri * Copyright IBM Corporation, 2007 * Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> * * Scaled math optimizations by Thomas Gleixner * Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de> * * Adaptive scheduling granularity, math enhancements by Peter Zijlstra * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> */ #include <linux/latencytop.h> #include <linux/sched.h> #include <linux/cpumask.h> /* * Targeted preemption latency for CPU-bound tasks: * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds) * * NOTE: this latency value is not the same as the concept of * 'timeslice length' - timeslices in CFS are of variable length * and have no persistent notion like in traditional, time-slice * based scheduling concepts. * * (to see the precise effective timeslice length of your workload, * run vmstat and monitor the context-switches (cs) field) */ unsigned int sysctl_sched_latency = 6000000ULL; unsigned int normalized_sysctl_sched_latency = 6000000ULL; /* * The initial- and re-scaling of tunables is configurable * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) * * Options are: * SCHED_TUNABLESCALING_NONE - unscaled, always *1 * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus */ enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG; /* * Minimal preemption granularity for CPU-bound tasks: * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds) */ unsigned int sysctl_sched_min_granularity = 750000ULL; unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; /* * is kept at sysctl_sched_latency / sysctl_sched_min_granularity */ static unsigned int sched_nr_latency = 8; /* * After fork, child runs first. If set to 0 (default) then * parent will (try to) run first. */ unsigned int sysctl_sched_child_runs_first __read_mostly; /* * SCHED_OTHER wake-up granularity. * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ unsigned int sysctl_sched_wakeup_granularity = 1000000UL; unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; /* * The exponential sliding window over which load is averaged for shares * distribution. * (default: 10msec) */ unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL; static const struct sched_class fair_sched_class; /************************************************************** * CFS operations on generic schedulable entities: */ #ifdef CONFIG_FAIR_GROUP_SCHED /* cpu runqueue to which this cfs_rq is attached */ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } /* An entity is a task if it doesn't "own" a runqueue */ #define entity_is_task(se) (!se->my_q) static inline struct task_struct *task_of(struct sched_entity *se) { #ifdef CONFIG_SCHED_DEBUG WARN_ON_ONCE(!entity_is_task(se)); #endif return container_of(se, struct task_struct, se); } /* Walk up scheduling entities hierarchy */ #define for_each_sched_entity(se) \ for (; se; se = se->parent) static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) { return p->se.cfs_rq; } /* runqueue on which this entity is (to be) queued */ static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) { return se->cfs_rq; } /* runqueue "owned" by this group */ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) { return grp->my_q; } /* Given a group's cfs_rq on one cpu, return its corresponding cfs_rq on * another cpu ('this_cpu') */ static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) { return cfs_rq->tg->cfs_rq[this_cpu]; } static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { if (!cfs_rq->on_list) { /* * Ensure we either appear before our parent (if already * enqueued) or force our parent to appear after us when it is * enqueued. The fact that we always enqueue bottom-up * reduces this to two cases. */ if (cfs_rq->tg->parent && cfs_rq->tg->parent->cfs_rq[cpu_of(rq_of(cfs_rq))]->on_list) { list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq_of(cfs_rq)->leaf_cfs_rq_list); } else { list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, &rq_of(cfs_rq)->leaf_cfs_rq_list); } cfs_rq->on_list = 1; } } static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) { if (cfs_rq->on_list) { list_del_rcu(&cfs_rq->leaf_cfs_rq_list); cfs_rq->on_list = 0; } } /* Iterate thr' all leaf cfs_rq's on a runqueue */ #define for_each_leaf_cfs_rq(rq, cfs_rq) \ list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) /* Do the two (enqueued) entities belong to the same group ? */ static inline int is_same_group(struct sched_entity *se, struct sched_entity *pse) { if (se->cfs_rq == pse->cfs_rq) return 1; return 0; } static inline struct sched_entity *parent_entity(struct sched_entity *se) { return se->parent; } /* return depth at which a sched entity is present in the hierarchy */ static inline int depth_se(struct sched_entity *se) { int depth = 0; for_each_sched_entity(se) depth++; return depth; } static void find_matching_se(struct sched_entity **se, struct sched_entity **pse) { int se_depth, pse_depth; /* * preemption test can be made between sibling entities who are in the * same cfs_rq i.e who have a common parent. Walk up the hierarchy of * both tasks until we find their ancestors who are siblings of common * parent. */ /* First walk up until both entities are at same depth */ se_depth = depth_se(*se); pse_depth = depth_se(*pse); while (se_depth > pse_depth) { se_depth--; *se = parent_entity(*se); } while (pse_depth > se_depth) { pse_depth--; *pse = parent_entity(*pse); } while (!is_same_group(*se, *pse)) { *se = parent_entity(*se); *pse = parent_entity(*pse); } } #else /* !CONFIG_FAIR_GROUP_SCHED */ static inline struct task_struct *task_of(struct sched_entity *se) { return container_of(se, struct task_struct, se); } static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return container_of(cfs_rq, struct rq, cfs); } #define entity_is_task(se) 1 #define for_each_sched_entity(se) \ for (; se; se = NULL) static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) { return &task_rq(p)->cfs; } static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) { struct task_struct *p = task_of(se); struct rq *rq = task_rq(p); return &rq->cfs; } /* runqueue "owned" by this group */ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) { return NULL; } static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) { return &cpu_rq(this_cpu)->cfs; } static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { } static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) { } #define for_each_leaf_cfs_rq(rq, cfs_rq) \ for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL) static inline int is_same_group(struct sched_entity *se, struct sched_entity *pse) { return 1; } static inline struct sched_entity *parent_entity(struct sched_entity *se) { return NULL; } static inline void find_matching_se(struct sched_entity **se, struct sched_entity **pse) { } #endif /* CONFIG_FAIR_GROUP_SCHED */ /************************************************************** * Scheduling class tree data structure manipulation methods: */ static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime) { s64 delta = (s64)(vruntime - min_vruntime); if (delta > 0) min_vruntime = vruntime; return min_vruntime; } static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) { s64 delta = (s64)(vruntime - min_vruntime); if (delta < 0) min_vruntime = vruntime; return min_vruntime; } static inline int entity_before(struct sched_entity *a, struct sched_entity *b) { return (s64)(a->vruntime - b->vruntime) < 0; } static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se) { return se->vruntime - cfs_rq->min_vruntime; } static void update_min_vruntime(struct cfs_rq *cfs_rq) { u64 vruntime = cfs_rq->min_vruntime; if (cfs_rq->curr) vruntime = cfs_rq->curr->vruntime; if (cfs_rq->rb_leftmost) { struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost, struct sched_entity, run_node); if (!cfs_rq->curr) vruntime = se->vruntime; else vruntime = min_vruntime(vruntime, se->vruntime); } cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); } /* * Enqueue an entity into the rb-tree: */ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { struct rb_node **link = &cfs_rq->tasks_timeline.rb_node; struct rb_node *parent = NULL; struct sched_entity *entry; s64 key = entity_key(cfs_rq, se); int leftmost = 1; /* * Find the right place in the rbtree: */ while (*link) { parent = *link; entry = rb_entry(parent, struct sched_entity, run_node); /* * We dont care about collisions. Nodes with * the same key stay together. */ if (key < entity_key(cfs_rq, entry)) { link = &parent->rb_left; } else { link = &parent->rb_right; leftmost = 0; } } /* * Maintain a cache of leftmost tree entries (it is frequently * used): */ if (leftmost) cfs_rq->rb_leftmost = &se->run_node; rb_link_node(&se->run_node, parent, link); rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); } static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { if (cfs_rq->rb_leftmost == &se->run_node) { struct rb_node *next_node; next_node = rb_next(&se->run_node); cfs_rq->rb_leftmost = next_node; } rb_erase(&se->run_node, &cfs_rq->tasks_timeline); } static struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq) { struct rb_node *left = cfs_rq->rb_leftmost; if (!left) return NULL; return rb_entry(left, struct sched_entity, run_node); } static struct sched_entity *__pick_next_entity(struct sched_entity *se) { struct rb_node *next = rb_next(&se->run_node); if (!next) return NULL; return rb_entry(next, struct sched_entity, run_node); } #ifdef CONFIG_SCHED_DEBUG static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) { struct rb_node *last = rb_last(&cfs_rq->tasks_timeline); if (!last) return NULL; return rb_entry(last, struct sched_entity, run_node); } /************************************************************** * Scheduling class statistics methods: */ int sched_proc_update_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); int factor = get_update_sysctl_factor(); if (ret || !write) return ret; sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency, sysctl_sched_min_granularity); #define WRT_SYSCTL(name) \ (normalized_sysctl_##name = sysctl_##name / (factor)) WRT_SYSCTL(sched_min_granularity); WRT_SYSCTL(sched_latency); WRT_SYSCTL(sched_wakeup_granularity); #undef WRT_SYSCTL return 0; } #endif /* * delta /= w */ static inline unsigned long calc_delta_fair(unsigned long delta, struct sched_entity *se) { if (unlikely(se->load.weight != NICE_0_LOAD)) delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load); return delta; } /* * The idea is to set a period in which each task runs once. * * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch * this period because otherwise the slices get too small. * * p = (nr <= nl) ? l : l*nr/nl */ static u64 __sched_period(unsigned long nr_running) { u64 period = sysctl_sched_latency; unsigned long nr_latency = sched_nr_latency; if (unlikely(nr_running > nr_latency)) { period = sysctl_sched_min_granularity; period *= nr_running; } return period; } /* * We calculate the wall-time slice from the period by taking a part * proportional to the weight. * * s = p*P[w/rw] */ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq); for_each_sched_entity(se) { struct load_weight *load; struct load_weight lw; cfs_rq = cfs_rq_of(se); load = &cfs_rq->load; if (unlikely(!se->on_rq)) { lw = cfs_rq->load; update_load_add(&lw, se->load.weight); load = &lw; } slice = calc_delta_mine(slice, se->load.weight, load); } return slice; } /* * We calculate the vruntime slice of a to be inserted task * * vs = s/w */ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) { return calc_delta_fair(sched_slice(cfs_rq, se), se); } static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update); static void update_cfs_shares(struct cfs_rq *cfs_rq); /* * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. */ static inline void __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, unsigned long delta_exec) { unsigned long delta_exec_weighted; schedstat_set(curr->statistics.exec_max, max((u64)delta_exec, curr->statistics.exec_max)); curr->sum_exec_runtime += delta_exec; schedstat_add(cfs_rq, exec_clock, delta_exec); delta_exec_weighted = calc_delta_fair(delta_exec, curr); curr->vruntime += delta_exec_weighted; update_min_vruntime(cfs_rq); #if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED cfs_rq->load_unacc_exec_time += delta_exec; #endif } static void update_curr(struct cfs_rq *cfs_rq) { struct sched_entity *curr = cfs_rq->curr; u64 now = rq_of(cfs_rq)->clock_task; unsigned long delta_exec; if (unlikely(!curr)) return; /* * Get the amount of time the current task was running * since the last time we changed load (this cannot * overflow on 32 bits): */ delta_exec = (unsigned long)(now - curr->exec_start); if (!delta_exec) return; __update_curr(cfs_rq, curr, delta_exec); curr->exec_start = now; if (entity_is_task(curr)) { struct task_struct *curtask = task_of(curr); trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime); cpuacct_charge(curtask, delta_exec); account_group_exec_runtime(curtask, delta_exec); } } static inline void update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock); } /* * Task is being enqueued - update stats: */ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { /* * Are we enqueueing a waiting task? (for current tasks * a dequeue/enqueue event is a NOP) */ if (se != cfs_rq->curr) update_stats_wait_start(cfs_rq, se); } static void update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max, rq_of(cfs_rq)->clock - se->statistics.wait_start)); schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1); schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum + rq_of(cfs_rq)->clock - se->statistics.wait_start); #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { trace_sched_stat_wait(task_of(se), rq_of(cfs_rq)->clock - se->statistics.wait_start); } #endif schedstat_set(se->statistics.wait_start, 0); } static inline void update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) { /* * Mark the end of the wait period if dequeueing a * waiting task: */ if (se != cfs_rq->curr) update_stats_wait_end(cfs_rq, se); } /* * We are picking a new current task - update its stats: */ static inline void update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { /* * We are starting a new run period: */ se->exec_start = rq_of(cfs_rq)->clock_task; } /************************************************** * Scheduling class queueing methods: */ #if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED static void add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) { cfs_rq->task_weight += weight; } #else static inline void add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) { } #endif static void account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { update_load_add(&cfs_rq->load, se->load.weight); if (!parent_entity(se)) inc_cpu_load(rq_of(cfs_rq), se->load.weight); if (entity_is_task(se)) { add_cfs_task_weight(cfs_rq, se->load.weight); list_add(&se->group_node, &cfs_rq->tasks); } cfs_rq->nr_running++; } static void account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) { update_load_sub(&cfs_rq->load, se->load.weight); if (!parent_entity(se)) dec_cpu_load(rq_of(cfs_rq), se->load.weight); if (entity_is_task(se)) { add_cfs_task_weight(cfs_rq, -se->load.weight); list_del_init(&se->group_node); } cfs_rq->nr_running--; } #ifdef CONFIG_FAIR_GROUP_SCHED # ifdef CONFIG_SMP static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq, int global_update) { struct task_group *tg = cfs_rq->tg; long load_avg; load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1); load_avg -= cfs_rq->load_contribution; if (global_update || abs(load_avg) > cfs_rq->load_contribution / 8) { atomic_add(load_avg, &tg->load_weight); cfs_rq->load_contribution += load_avg; } } static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update) { u64 period = sysctl_sched_shares_window; u64 now, delta; unsigned long load = cfs_rq->load.weight; if (cfs_rq->tg == &root_task_group) return; now = rq_of(cfs_rq)->clock_task; delta = now - cfs_rq->load_stamp; /* truncate load history at 4 idle periods */ if (cfs_rq->load_stamp > cfs_rq->load_last && now - cfs_rq->load_last > 4 * period) { cfs_rq->load_period = 0; cfs_rq->load_avg = 0; delta = period - 1; } cfs_rq->load_stamp = now; cfs_rq->load_unacc_exec_time = 0; cfs_rq->load_period += delta; if (load) { cfs_rq->load_last = now; cfs_rq->load_avg += delta * load; } /* consider updating load contribution on each fold or truncate */ if (global_update || cfs_rq->load_period > period || !cfs_rq->load_period) update_cfs_rq_load_contribution(cfs_rq, global_update); while (cfs_rq->load_period > period) { /* * Inline assembly required to prevent the compiler * optimising this loop into a divmod call. * See __iter_div_u64_rem() for another example of this. */ asm("" : "+rm" (cfs_rq->load_period)); cfs_rq->load_period /= 2; cfs_rq->load_avg /= 2; } if (!cfs_rq->curr && !cfs_rq->nr_running && !cfs_rq->load_avg) list_del_leaf_cfs_rq(cfs_rq); } static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) { long load_weight, load, shares; load = cfs_rq->load.weight; load_weight = atomic_read(&tg->load_weight); load_weight += load; load_weight -= cfs_rq->load_contribution; shares = (tg->shares * load); if (load_weight) shares /= load_weight; if (shares < MIN_SHARES) shares = MIN_SHARES; if (shares > tg->shares) shares = tg->shares; return shares; } static void update_entity_shares_tick(struct cfs_rq *cfs_rq) { if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) { update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq); } } # else /* CONFIG_SMP */ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update) { } static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) { return tg->shares; } static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq) { } # endif /* CONFIG_SMP */ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, unsigned long weight) { if (se->on_rq) { /* commit outstanding execution time */ if (cfs_rq->curr == se) update_curr(cfs_rq); account_entity_dequeue(cfs_rq, se); } update_load_set(&se->load, weight); if (se->on_rq) account_entity_enqueue(cfs_rq, se); } static void update_cfs_shares(struct cfs_rq *cfs_rq) { struct task_group *tg; struct sched_entity *se; long shares; tg = cfs_rq->tg; se = tg->se[cpu_of(rq_of(cfs_rq))]; if (!se) return; #ifndef CONFIG_SMP if (likely(se->load.weight == tg->shares)) return; #endif shares = calc_cfs_shares(cfs_rq, tg); reweight_entity(cfs_rq_of(se), se, shares); } #else /* CONFIG_FAIR_GROUP_SCHED */ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update) { } static inline void update_cfs_shares(struct cfs_rq *cfs_rq) { } static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq) { } #endif /* CONFIG_FAIR_GROUP_SCHED */ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) { #ifdef CONFIG_SCHEDSTATS struct task_struct *tsk = NULL; if (entity_is_task(se)) tsk = task_of(se); if (se->statistics.sleep_start) { u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start; if ((s64)delta < 0) delta = 0; if (unlikely(delta > se->statistics.sleep_max)) se->statistics.sleep_max = delta; se->statistics.sleep_start = 0; se->statistics.sum_sleep_runtime += delta; if (tsk) { account_scheduler_latency(tsk, delta >> 10, 1); trace_sched_stat_sleep(tsk, delta); } } if (se->statistics.block_start) { u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start; if ((s64)delta < 0) delta = 0; if (unlikely(delta > se->statistics.block_max)) se->statistics.block_max = delta; se->statistics.block_start = 0; se->statistics.sum_sleep_runtime += delta; if (tsk) { if (tsk->in_iowait) { se->statistics.iowait_sum += delta; se->statistics.iowait_count++; trace_sched_stat_iowait(tsk, delta); } /* * Blocking time is in units of nanosecs, so shift by * 20 to get a milliseconds-range estimation of the * amount of time that the task spent sleeping: */ if (unlikely(prof_on == SLEEP_PROFILING)) { profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk), delta >> 20); } account_scheduler_latency(tsk, delta >> 10, 0); } } #endif } static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) { #ifdef CONFIG_SCHED_DEBUG s64 d = se->vruntime - cfs_rq->min_vruntime; if (d < 0) d = -d; if (d > 3*sysctl_sched_latency) schedstat_inc(cfs_rq, nr_spread_over); #endif } static void place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) { u64 vruntime = cfs_rq->min_vruntime; /* * The 'current' period is already promised to the current tasks, * however the extra weight of the new task will slow them down a * little, place the new task so that it fits in the slot that * stays open at the end. */ if (initial && sched_feat(START_DEBIT)) vruntime += sched_vslice(cfs_rq, se); /* sleeps up to a single latency don't count. */ if (!initial) { unsigned long thresh = sysctl_sched_latency; /* * Halve their sleep time's effect, to allow * for a gentler effect of sleepers: */ if (sched_feat(GENTLE_FAIR_SLEEPERS)) thresh >>= 1; vruntime -= thresh; } /* ensure we never gain time by being placed backwards. */ vruntime = max_vruntime(se->vruntime, vruntime); se->vruntime = vruntime; } static void enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { /* * Update the normalized vruntime before updating min_vruntime * through callig update_curr(). */ if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING)) se->vruntime += cfs_rq->min_vruntime; /* * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); update_cfs_load(cfs_rq, 0); account_entity_enqueue(cfs_rq, se); update_cfs_shares(cfs_rq); if (flags & ENQUEUE_WAKEUP) { place_entity(cfs_rq, se, 0); enqueue_sleeper(cfs_rq, se); } update_stats_enqueue(cfs_rq, se); check_spread(cfs_rq, se); if (se != cfs_rq->curr) __enqueue_entity(cfs_rq, se); se->on_rq = 1; if (cfs_rq->nr_running == 1) list_add_leaf_cfs_rq(cfs_rq); } static void __clear_buddies_last(struct sched_entity *se) { for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); if (cfs_rq->last == se) cfs_rq->last = NULL; else break; } } static void __clear_buddies_next(struct sched_entity *se) { for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); if (cfs_rq->next == se) cfs_rq->next = NULL; else break; } } static void __clear_buddies_skip(struct sched_entity *se) { for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); if (cfs_rq->skip == se) cfs_rq->skip = NULL; else break; } } static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) { if (cfs_rq->last == se) __clear_buddies_last(se); if (cfs_rq->next == se) __clear_buddies_next(se); if (cfs_rq->skip == se) __clear_buddies_skip(se); } static void dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { /* * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); update_stats_dequeue(cfs_rq, se); if (flags & DEQUEUE_SLEEP) { #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { struct task_struct *tsk = task_of(se); if (tsk->state & TASK_INTERRUPTIBLE) se->statistics.sleep_start = rq_of(cfs_rq)->clock; if (tsk->state & TASK_UNINTERRUPTIBLE) se->statistics.block_start = rq_of(cfs_rq)->clock; } #endif } clear_buddies(cfs_rq, se); if (se != cfs_rq->curr) __dequeue_entity(cfs_rq, se); se->on_rq = 0; update_cfs_load(cfs_rq, 0); account_entity_dequeue(cfs_rq, se); update_min_vruntime(cfs_rq); update_cfs_shares(cfs_rq); /* * Normalize the entity after updating the min_vruntime because the * update can refer to the ->curr item and we need to reflect this * movement in our normalized position. */ if (!(flags & DEQUEUE_SLEEP)) se->vruntime -= cfs_rq->min_vruntime; } /* * Preempt the current task with a newly woken task if needed: */ static void check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { unsigned long ideal_runtime, delta_exec; ideal_runtime = sched_slice(cfs_rq, curr); delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; if (delta_exec > ideal_runtime) { resched_task(rq_of(cfs_rq)->curr); /* * The current task ran long enough, ensure it doesn't get * re-elected due to buddy favours. */ clear_buddies(cfs_rq, curr); return; } /* * Ensure that a task that missed wakeup preemption by a * narrow margin doesn't have to wait for a full slice. * This also mitigates buddy induced latencies under load. */ if (!sched_feat(WAKEUP_PREEMPT)) return; if (delta_exec < sysctl_sched_min_granularity) return; if (cfs_rq->nr_running > 1) { struct sched_entity *se = __pick_first_entity(cfs_rq); s64 delta = curr->vruntime - se->vruntime; if (delta < 0) return; if (delta > ideal_runtime) resched_task(rq_of(cfs_rq)->curr); } } static void set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) { /* 'current' is not kept within the tree. */ if (se->on_rq) { /* * Any task has to be enqueued before it get to execute on * a CPU. So account for the time it spent waiting on the * runqueue. */ update_stats_wait_end(cfs_rq, se); __dequeue_entity(cfs_rq, se); } update_stats_curr_start(cfs_rq, se); cfs_rq->curr = se; #ifdef CONFIG_SCHEDSTATS /* * Track our maximum slice length, if the CPU's load is at * least twice that of our own weight (i.e. dont track it * when there are only lesser-weight tasks around): */ if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) { se->statistics.slice_max = max(se->statistics.slice_max, se->sum_exec_runtime - se->prev_sum_exec_runtime); } #endif se->prev_sum_exec_runtime = se->sum_exec_runtime; } static int wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); /* * Pick the next process, keeping these things in mind, in this order: * 1) keep things fair between processes/task groups * 2) pick the "next" process, since someone really wants that to run * 3) pick the "last" process, for cache locality * 4) do not run the "skip" process, if something else is available */ static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) { struct sched_entity *se = __pick_first_entity(cfs_rq); struct sched_entity *left = se; /* * Avoid running the skip buddy, if running something else can * be done without getting too unfair. */ if (cfs_rq->skip == se) { struct sched_entity *second = __pick_next_entity(se); if (second && wakeup_preempt_entity(second, left) < 1) se = second; } /* * Prefer last buddy, try to return the CPU to a preempted task. */ if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1) se = cfs_rq->last; /* * Someone really wants this to run. If it's not unfair, run it. */ if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1) se = cfs_rq->next; clear_buddies(cfs_rq, se); return se; } static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) { /* * If still on the runqueue then deactivate_task() * was not called and update_curr() has to be done: */ if (prev->on_rq) update_curr(cfs_rq); check_spread(cfs_rq, prev); if (prev->on_rq) { update_stats_wait_start(cfs_rq, prev); /* Put 'current' back into the tree. */ __enqueue_entity(cfs_rq, prev); } cfs_rq->curr = NULL; } static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) { /* * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); /* * Update share accounting for long-running entities. */ update_entity_shares_tick(cfs_rq); #ifdef CONFIG_SCHED_HRTICK /* * queued ticks are scheduled to match the slice, so don't bother * validating it and just reschedule. */ if (queued) { resched_task(rq_of(cfs_rq)->curr); return; } /* * don't let the period tick interfere with the hrtick preemption */ if (!sched_feat(DOUBLE_TICK) && hrtimer_active(&rq_of(cfs_rq)->hrtick_timer)) return; #endif if (cfs_rq->nr_running > 1 || !sched_feat(WAKEUP_PREEMPT)) check_preempt_tick(cfs_rq, curr); } /************************************************** * CFS operations on tasks: */ #ifdef CONFIG_SCHED_HRTICK static void hrtick_start_fair(struct rq *rq, struct task_struct *p) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); WARN_ON(task_rq(p) != rq); if (hrtick_enabled(rq) && cfs_rq->nr_running > 1) { u64 slice = sched_slice(cfs_rq, se); u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime; s64 delta = slice - ran; if (delta < 0) { if (rq->curr == p) resched_task(p); return; } /* * Don't schedule slices shorter than 10000ns, that just * doesn't make sense. Rely on vruntime for fairness. */ if (rq->curr != p) delta = max_t(s64, 10000LL, delta); hrtick_start(rq, delta); } } /* * called from enqueue/dequeue and updates the hrtick when the * current task is from our class and nr_running is low enough * to matter. */ static void hrtick_update(struct rq *rq) { struct task_struct *curr = rq->curr; if (curr->sched_class != &fair_sched_class) return; if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency) hrtick_start_fair(rq, curr); } #else /* !CONFIG_SCHED_HRTICK */ static inline void hrtick_start_fair(struct rq *rq, struct task_struct *p) { } static inline void hrtick_update(struct rq *rq) { } #endif /* * The enqueue_task method is called before nr_running is * increased. Here we update the fair scheduling stats and * then put the task into the rbtree: */ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; for_each_sched_entity(se) { if (se->on_rq) break; cfs_rq = cfs_rq_of(se); enqueue_entity(cfs_rq, se, flags); flags = ENQUEUE_WAKEUP; } for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq); } hrtick_update(rq); } /* * The dequeue_task method is called before nr_running is * decreased. We remove the task from the rbtree and * update the fair scheduling stats: */ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); dequeue_entity(cfs_rq, se, flags); /* Don't dequeue parent if it has other entities besides us */ if (cfs_rq->load.weight) break; flags |= DEQUEUE_SLEEP; } for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq); } hrtick_update(rq); } #ifdef CONFIG_SMP static void task_waking_fair(struct rq *rq, struct task_struct *p) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); se->vruntime -= cfs_rq->min_vruntime; } #ifdef CONFIG_FAIR_GROUP_SCHED /* * effective_load() calculates the load change as seen from the root_task_group * * Adding load to a group doesn't make a group heavier, but can cause movement * of group shares between cpus. Assuming the shares were perfectly aligned one * can calculate the shift in shares. */ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) { struct sched_entity *se = tg->se[cpu]; if (!tg->parent) return wl; for_each_sched_entity(se) { long lw, w; tg = se->my_q->tg; w = se->my_q->load.weight; /* use this cpu's instantaneous contribution */ lw = atomic_read(&tg->load_weight); lw -= se->my_q->load_contribution; lw += w + wg; wl += w; if (lw > 0 && wl < lw) wl = (wl * tg->shares) / lw; else wl = tg->shares; /* zero point is MIN_SHARES */ if (wl < MIN_SHARES) wl = MIN_SHARES; wl -= se->load.weight; wg = 0; } return wl; } #else static inline unsigned long effective_load(struct task_group *tg, int cpu, unsigned long wl, unsigned long wg) { return wl; } #endif static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) { s64 this_load, load; int idx, this_cpu, prev_cpu; unsigned long tl_per_task; struct task_group *tg; unsigned long weight; int balanced; idx = sd->wake_idx; this_cpu = smp_processor_id(); prev_cpu = task_cpu(p); load = source_load(prev_cpu, idx); this_load = target_load(this_cpu, idx); /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load * of the current CPU: */ rcu_read_lock(); if (sync) { tg = task_group(current); weight = current->se.load.weight; this_load += effective_load(tg, this_cpu, -weight, -weight); load += effective_load(tg, prev_cpu, 0, -weight); } tg = task_group(p); weight = p->se.load.weight; /* * In low-load situations, where prev_cpu is idle and this_cpu is idle * due to the sync cause above having dropped this_load to 0, we'll * always have an imbalance, but there's really nothing you can do * about that, so that's good too. * * Otherwise check if either cpus are near enough in load to allow this * task to be woken on this_cpu. */ if (this_load > 0) { s64 this_eff_load, prev_eff_load; this_eff_load = 100; this_eff_load *= power_of(prev_cpu); this_eff_load *= this_load + effective_load(tg, this_cpu, weight, weight); prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2; prev_eff_load *= power_of(this_cpu); prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight); balanced = this_eff_load <= prev_eff_load; } else balanced = true; rcu_read_unlock(); /* * If the currently running task will sleep within * a reasonable amount of time then attract this newly * woken task: */ if (sync && balanced) return 1; schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); if (balanced || (this_load <= load && this_load + target_load(prev_cpu, idx) <= tl_per_task)) { /* * This domain has SD_WAKE_AFFINE and * p is cache cold in this domain, and * there is no bad imbalance. */ schedstat_inc(sd, ttwu_move_affine); schedstat_inc(p, se.statistics.nr_wakeups_affine); return 1; } return 0; } /* * find_idlest_group finds and returns the least busy CPU group within the * domain. */ static struct sched_group * find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu, int load_idx) { struct sched_group *idlest = NULL, *group = sd->groups; unsigned long min_load = ULONG_MAX, this_load = 0; int imbalance = 100 + (sd->imbalance_pct-100)/2; do { unsigned long load, avg_load; int local_group; int i; /* Skip over this group if it has no CPUs allowed */ if (!cpumask_intersects(sched_group_cpus(group), &p->cpus_allowed)) continue; local_group = cpumask_test_cpu(this_cpu, sched_group_cpus(group)); /* Tally up the load of all CPUs in the group */ avg_load = 0; for_each_cpu(i, sched_group_cpus(group)) { /* Bias balancing toward cpus of our domain */ if (local_group) load = source_load(i, load_idx); else load = target_load(i, load_idx); avg_load += load; } /* Adjust by relative CPU power of the group */ avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power; if (local_group) { this_load = avg_load; } else if (avg_load < min_load) { min_load = avg_load; idlest = group; } } while (group = group->next, group != sd->groups); if (!idlest || 100*this_load < imbalance*min_load) return NULL; return idlest; } /* * find_idlest_cpu - find the idlest cpu among the cpus in group. */ static int find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) { unsigned long load, min_load = ULONG_MAX; int idlest = -1; int i; /* Traverse only the allowed CPUs */ for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { load = weighted_cpuload(i); if (load < min_load || (load == min_load && i == this_cpu)) { min_load = load; idlest = i; } } return idlest; } /* * Try and locate an idle CPU in the sched_domain. */ static int select_idle_sibling(struct task_struct *p, int target) { int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); struct sched_domain *sd; int i; /* * If the task is going to be woken-up on this cpu and if it is * already idle, then it is the right target. */ if (target == cpu && idle_cpu(cpu)) return cpu; /* * If the task is going to be woken-up on the cpu where it previously * ran and if it is currently idle, then it the right target. */ if (target == prev_cpu && idle_cpu(prev_cpu)) return prev_cpu; /* * Otherwise, iterate the domains and find an elegible idle cpu. */ for_each_domain(target, sd) { if (!(sd->flags & SD_SHARE_PKG_RESOURCES)) break; for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) { if (idle_cpu(i)) { target = i; break; } } /* * Lets stop looking for an idle sibling when we reached * the domain that spans the current cpu and prev_cpu. */ if (cpumask_test_cpu(cpu, sched_domain_span(sd)) && cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) break; } return target; } /* * sched_balance_self: balance the current task (running on cpu) in domains * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and * SD_BALANCE_EXEC. * * Balance, ie. select the least loaded group. * * Returns the target CPU number, or the same CPU if no balancing is needed. * * preempt must be disabled. */ static int select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_flags) { struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; int want_sd = 1; int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { if (cpumask_test_cpu(cpu, &p->cpus_allowed)) want_affine = 1; new_cpu = prev_cpu; } for_each_domain(cpu, tmp) { if (!(tmp->flags & SD_LOAD_BALANCE)) continue; /* * If power savings logic is enabled for a domain, see if we * are not overloaded, if so, don't balance wider. */ if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) { unsigned long power = 0; unsigned long nr_running = 0; unsigned long capacity; int i; for_each_cpu(i, sched_domain_span(tmp)) { power += power_of(i); nr_running += cpu_rq(i)->cfs.nr_running; } capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); if (tmp->flags & SD_POWERSAVINGS_BALANCE) nr_running /= 2; if (nr_running < capacity) want_sd = 0; } /* * If both cpu and prev_cpu are part of this domain, * cpu is a valid SD_WAKE_AFFINE target. */ if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { affine_sd = tmp; want_affine = 0; } if (!want_sd && !want_affine) break; if (!(tmp->flags & sd_flag)) continue; if (want_sd) sd = tmp; } if (affine_sd) { if (cpu == prev_cpu || wake_affine(affine_sd, p, sync)) return select_idle_sibling(p, cpu); else return select_idle_sibling(p, prev_cpu); } while (sd) { int load_idx = sd->forkexec_idx; struct sched_group *group; int weight; if (!(sd->flags & sd_flag)) { sd = sd->child; continue; } if (sd_flag & SD_BALANCE_WAKE) load_idx = sd->wake_idx; group = find_idlest_group(sd, p, cpu, load_idx); if (!group) { sd = sd->child; continue; } new_cpu = find_idlest_cpu(group, p, cpu); if (new_cpu == -1 || new_cpu == cpu) { /* Now try balancing at a lower domain level of cpu */ sd = sd->child; continue; } /* Now try balancing at a lower domain level of new_cpu */ cpu = new_cpu; weight = sd->span_weight; sd = NULL; for_each_domain(cpu, tmp) { if (weight <= tmp->span_weight) break; if (tmp->flags & sd_flag) sd = tmp; } /* while loop will break here if sd == NULL */ } return new_cpu; } #endif /* CONFIG_SMP */ static unsigned long wakeup_gran(struct sched_entity *curr, struct sched_entity *se) { unsigned long gran = sysctl_sched_wakeup_granularity; /* * Since its curr running now, convert the gran from real-time * to virtual-time in his units. * * By using 'se' instead of 'curr' we penalize light tasks, so * they get preempted easier. That is, if 'se' < 'curr' then * the resulting gran will be larger, therefore penalizing the * lighter, if otoh 'se' > 'curr' then the resulting gran will * be smaller, again penalizing the lighter task. * * This is especially important for buddies when the leftmost * task is higher priority than the buddy. */ if (unlikely(se->load.weight != NICE_0_LOAD)) gran = calc_delta_fair(gran, se); return gran; } /* * Should 'se' preempt 'curr'. * * |s1 * |s2 * |s3 * g * |<--->|c * * w(c, s1) = -1 * w(c, s2) = 0 * w(c, s3) = 1 * */ static int wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) { s64 gran, vdiff = curr->vruntime - se->vruntime; if (vdiff <= 0) return -1; gran = wakeup_gran(curr, se); if (vdiff > gran) return 1; return 0; } static void set_last_buddy(struct sched_entity *se) { if (likely(task_of(se)->policy != SCHED_IDLE)) { for_each_sched_entity(se) cfs_rq_of(se)->last = se; } } static void set_next_buddy(struct sched_entity *se) { if (likely(task_of(se)->policy != SCHED_IDLE)) { for_each_sched_entity(se) cfs_rq_of(se)->next = se; } } static void set_skip_buddy(struct sched_entity *se) { if (likely(task_of(se)->policy != SCHED_IDLE)) { for_each_sched_entity(se) cfs_rq_of(se)->skip = se; } } /* * Preempt the current task with a newly woken task if needed: */ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; struct cfs_rq *cfs_rq = task_cfs_rq(curr); int scale = cfs_rq->nr_running >= sched_nr_latency; if (unlikely(se == pse)) return; if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) set_next_buddy(pse); /* * We can come here with TIF_NEED_RESCHED already set from new task * wake up path. */ if (test_tsk_need_resched(curr)) return; /* Idle tasks are by definition preempted by non-idle tasks. */ if (unlikely(curr->policy == SCHED_IDLE) && likely(p->policy != SCHED_IDLE)) goto preempt; /* * Batch and idle tasks do not preempt non-idle tasks (their preemption * is driven by the tick): */ if (unlikely(p->policy != SCHED_NORMAL)) return; if (!sched_feat(WAKEUP_PREEMPT)) return; update_curr(cfs_rq); find_matching_se(&se, &pse); BUG_ON(!pse); if (wakeup_preempt_entity(se, pse) == 1) goto preempt; return; preempt: resched_task(curr); /* * Only set the backward buddy when the current task is still * on the rq. This can happen when a wakeup gets interleaved * with schedule on the ->pre_schedule() or idle_balance() * point, either of which can * drop the rq lock. * * Also, during early boot the idle thread is in the fair class, * for obvious reasons its a bad idea to schedule back to it. */ if (unlikely(!se->on_rq || curr == rq->idle)) return; if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se)) set_last_buddy(se); } static struct task_struct *pick_next_task_fair(struct rq *rq) { struct task_struct *p; struct cfs_rq *cfs_rq = &rq->cfs; struct sched_entity *se; if (!cfs_rq->nr_running) return NULL; do { se = pick_next_entity(cfs_rq); set_next_entity(cfs_rq, se); cfs_rq = group_cfs_rq(se); } while (cfs_rq); p = task_of(se); hrtick_start_fair(rq, p); return p; } /* * Account for a descheduled task: */ static void put_prev_task_fair(struct rq *rq, struct task_struct *prev) { struct sched_entity *se = &prev->se; struct cfs_rq *cfs_rq; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); put_prev_entity(cfs_rq, se); } } /* * sched_yield() is very simple * * The magic of dealing with the ->skip buddy is in pick_next_entity. */ static void yield_task_fair(struct rq *rq) { struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); struct sched_entity *se = &curr->se; /* * Are we the only task in the tree? */ if (unlikely(rq->nr_running == 1)) return; clear_buddies(cfs_rq, se); if (curr->policy != SCHED_BATCH) { update_rq_clock(rq); /* * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); } set_skip_buddy(se); } static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt) { struct sched_entity *se = &p->se; if (!se->on_rq) return false; /* Tell the scheduler that we'd really like pse to run next. */ set_next_buddy(se); yield_task_fair(rq); return true; } #ifdef CONFIG_SMP /************************************************** * Fair scheduling class load-balancing methods: */ /* * pull_task - move a task from a remote runqueue to the local runqueue. * Both runqueues must be locked. */ static void pull_task(struct rq *src_rq, struct task_struct *p, struct rq *this_rq, int this_cpu) { deactivate_task(src_rq, p, 0); set_task_cpu(p, this_cpu); activate_task(this_rq, p, 0); check_preempt_curr(this_rq, p, 0); } /* * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? */ static int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned) { int tsk_cache_hot = 0; /* * We do not migrate tasks that are: * 1) running (obviously), or * 2) cannot be migrated to this CPU due to cpus_allowed, or * 3) are cache-hot on their current CPU. */ if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { schedstat_inc(p, se.statistics.nr_failed_migrations_affine); return 0; } *all_pinned = 0; if (task_running(rq, p)) { schedstat_inc(p, se.statistics.nr_failed_migrations_running); return 0; } /* * Aggressive migration if: * 1) task is cache cold, or * 2) too many balance attempts have failed. */ tsk_cache_hot = task_hot(p, rq->clock_task, sd); if (!tsk_cache_hot || sd->nr_balance_failed > sd->cache_nice_tries) { #ifdef CONFIG_SCHEDSTATS if (tsk_cache_hot) { schedstat_inc(sd, lb_hot_gained[idle]); schedstat_inc(p, se.statistics.nr_forced_migrations); } #endif return 1; } if (tsk_cache_hot) { schedstat_inc(p, se.statistics.nr_failed_migrations_hot); return 0; } return 1; } /* * move_one_task tries to move exactly one task from busiest to this_rq, as * part of active balancing operations within "domain". * Returns 1 if successful and 0 otherwise. * * Called with both runqueues locked. */ static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, struct sched_domain *sd, enum cpu_idle_type idle) { struct task_struct *p, *n; struct cfs_rq *cfs_rq; int pinned = 0; for_each_leaf_cfs_rq(busiest, cfs_rq) { list_for_each_entry_safe(p, n, &cfs_rq->tasks, se.group_node) { if (!can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) continue; pull_task(busiest, p, this_rq, this_cpu); /* * Right now, this is only the second place pull_task() * is called, so we can safely collect pull_task() * stats here rather than inside pull_task(). */ schedstat_inc(sd, lb_gained[idle]); return 1; } } return 0; } static unsigned long balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio, struct cfs_rq *busiest_cfs_rq) { int loops = 0, pulled = 0, pinned = 0; long rem_load_move = max_load_move; struct task_struct *p, *n; if (max_load_move == 0) goto out; pinned = 1; list_for_each_entry_safe(p, n, &busiest_cfs_rq->tasks, se.group_node) { if (loops++ > sysctl_sched_nr_migrate) break; if ((p->se.load.weight >> 1) > rem_load_move || !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) continue; pull_task(busiest, p, this_rq, this_cpu); pulled++; rem_load_move -= p->se.load.weight; #ifdef CONFIG_PREEMPT /* * NEWIDLE balancing is a source of latency, so preemptible * kernels will stop after the first task is pulled to minimize * the critical section. */ if (idle == CPU_NEWLY_IDLE) break; #endif /* * We only want to steal up to the prescribed amount of * weighted load. */ if (rem_load_move <= 0) break; if (p->prio < *this_best_prio) *this_best_prio = p->prio; } out: /* * Right now, this is one of only two places pull_task() is called, * so we can safely collect pull_task() stats here rather than * inside pull_task(). */ schedstat_add(sd, lb_gained[idle], pulled); if (all_pinned) *all_pinned = pinned; return max_load_move - rem_load_move; } #ifdef CONFIG_FAIR_GROUP_SCHED /* * update tg->load_weight by folding this cpu's load_avg */ static int update_shares_cpu(struct task_group *tg, int cpu) { struct cfs_rq *cfs_rq; unsigned long flags; struct rq *rq; if (!tg->se[cpu]) return 0; rq = cpu_rq(cpu); cfs_rq = tg->cfs_rq[cpu]; raw_spin_lock_irqsave(&rq->lock, flags); update_rq_clock(rq); update_cfs_load(cfs_rq, 1); /* * We need to update shares after updating tg->load_weight in * order to adjust the weight of groups with long running tasks. */ update_cfs_shares(cfs_rq); raw_spin_unlock_irqrestore(&rq->lock, flags); return 0; } static void update_shares(int cpu) { struct cfs_rq *cfs_rq; struct rq *rq = cpu_rq(cpu); rcu_read_lock(); for_each_leaf_cfs_rq(rq, cfs_rq) update_shares_cpu(cfs_rq->tg, cpu); rcu_read_unlock(); } static unsigned long load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio) { long rem_load_move = max_load_move; int busiest_cpu = cpu_of(busiest); struct task_group *tg; rcu_read_lock(); update_h_load(busiest_cpu); list_for_each_entry_rcu(tg, &task_groups, list) { struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu]; unsigned long busiest_h_load = busiest_cfs_rq->h_load; unsigned long busiest_weight = busiest_cfs_rq->load.weight; u64 rem_load, moved_load; /* * empty group */ if (!busiest_cfs_rq->task_weight) continue; rem_load = (u64)rem_load_move * busiest_weight; rem_load = div_u64(rem_load, busiest_h_load + 1); moved_load = balance_tasks(this_rq, this_cpu, busiest, rem_load, sd, idle, all_pinned, this_best_prio, busiest_cfs_rq); if (!moved_load) continue; moved_load *= busiest_h_load; moved_load = div_u64(moved_load, busiest_weight + 1); rem_load_move -= moved_load; if (rem_load_move < 0) break; } rcu_read_unlock(); return max_load_move - rem_load_move; } #else static inline void update_shares(int cpu) { } static unsigned long load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio) { return balance_tasks(this_rq, this_cpu, busiest, max_load_move, sd, idle, all_pinned, this_best_prio, &busiest->cfs); } #endif /* * move_tasks tries to move up to max_load_move weighted load from busiest to * this_rq, as part of a balancing operation within domain "sd". * Returns 1 if successful and 0 otherwise. * * Called with both runqueues locked. */ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned) { unsigned long total_load_moved = 0, load_moved; int this_best_prio = this_rq->curr->prio; do { load_moved = load_balance_fair(this_rq, this_cpu, busiest, max_load_move - total_load_moved, sd, idle, all_pinned, &this_best_prio); total_load_moved += load_moved; #ifdef CONFIG_PREEMPT /* * NEWIDLE balancing is a source of latency, so preemptible * kernels will stop after the first task is pulled to minimize * the critical section. */ if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) break; if (raw_spin_is_contended(&this_rq->lock) || raw_spin_is_contended(&busiest->lock)) break; #endif } while (load_moved && max_load_move > total_load_moved); return total_load_moved > 0; } /********** Helpers for find_busiest_group ************************/ /* * sd_lb_stats - Structure to store the statistics of a sched_domain * during load balancing. */ struct sd_lb_stats { struct sched_group *busiest; /* Busiest group in this sd */ struct sched_group *this; /* Local group in this sd */ unsigned long total_load; /* Total load of all groups in sd */ unsigned long total_pwr; /* Total power of all groups in sd */ unsigned long avg_load; /* Average load across all groups in sd */ /** Statistics of this group */ unsigned long this_load; unsigned long this_load_per_task; unsigned long this_nr_running; unsigned long this_has_capacity; unsigned int this_idle_cpus; /* Statistics of the busiest group */ unsigned int busiest_idle_cpus; unsigned long max_load; unsigned long busiest_load_per_task; unsigned long busiest_nr_running; unsigned long busiest_group_capacity; unsigned long busiest_has_capacity; unsigned int busiest_group_weight; int group_imb; /* Is there imbalance in this sd */ #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) int power_savings_balance; /* Is powersave balance needed for this sd */ struct sched_group *group_min; /* Least loaded group in sd */ struct sched_group *group_leader; /* Group which relieves group_min */ unsigned long min_load_per_task; /* load_per_task in group_min */ unsigned long leader_nr_running; /* Nr running of group_leader */ unsigned long min_nr_running; /* Nr running of group_min */ #endif }; /* * sg_lb_stats - stats of a sched_group required for load_balancing */ struct sg_lb_stats { unsigned long avg_load; /*Avg load across the CPUs of the group */ unsigned long group_load; /* Total load over the CPUs of the group */ unsigned long sum_nr_running; /* Nr tasks running in the group */ unsigned long sum_weighted_load; /* Weighted load of group's tasks */ unsigned long group_capacity; unsigned long idle_cpus; unsigned long group_weight; int group_imb; /* Is there an imbalance in the group ? */ int group_has_capacity; /* Is there extra capacity in the group? */ }; /** * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. * @group: The group whose first cpu is to be returned. */ static inline unsigned int group_first_cpu(struct sched_group *group) { return cpumask_first(sched_group_cpus(group)); } /** * get_sd_load_idx - Obtain the load index for a given sched domain. * @sd: The sched_domain whose load_idx is to be obtained. * @idle: The Idle status of the CPU for whose sd load_icx is obtained. */ static inline int get_sd_load_idx(struct sched_domain *sd, enum cpu_idle_type idle) { int load_idx; switch (idle) { case CPU_NOT_IDLE: load_idx = sd->busy_idx; break; case CPU_NEWLY_IDLE: load_idx = sd->newidle_idx; break; default: load_idx = sd->idle_idx; break; } return load_idx; } #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) /** * init_sd_power_savings_stats - Initialize power savings statistics for * the given sched_domain, during load balancing. * * @sd: Sched domain whose power-savings statistics are to be initialized. * @sds: Variable containing the statistics for sd. * @idle: Idle status of the CPU at which we're performing load-balancing. */ static inline void init_sd_power_savings_stats(struct sched_domain *sd, struct sd_lb_stats *sds, enum cpu_idle_type idle) { /* * Busy processors will not participate in power savings * balance. */ if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) sds->power_savings_balance = 0; else { sds->power_savings_balance = 1; sds->min_nr_running = ULONG_MAX; sds->leader_nr_running = 0;


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