diff -urpN -X /home/fletch/.diff.exclude 105-numameminfo/Documentation/filesystems/proc.txt 114-sched_tunables/Documentation/filesystems/proc.txt --- 105-numameminfo/Documentation/filesystems/proc.txt Sat Jun 14 18:37:23 2003 +++ 114-sched_tunables/Documentation/filesystems/proc.txt Tue Sep 2 10:09:31 2003 @@ -37,6 +37,7 @@ Table of Contents 2.8 /proc/sys/net/ipv4 - IPV4 settings 2.9 Appletalk 2.10 IPX + 2.11 /proc/sys/sched - scheduler tunables ------------------------------------------------------------------------------ Preface @@ -1751,6 +1752,104 @@ IPX. The /proc/net/ipx_route table holds a list of IPX routes. For each route it gives the destination network, the router node (or Directly) and the network address of the router (or Connected) for internal networks. + +2.11 /proc/sys/sched - scheduler tunables +----------------------------------------- + +Useful knobs for tuning the scheduler live in /proc/sys/sched. + +child_penalty +------------- + +Percentage of the parent's sleep_avg that children inherit. sleep_avg is +a running average of the time a process spends sleeping. Tasks with high +sleep_avg values are considered interactive and given a higher dynamic +priority and a larger timeslice. You typically want this some value just +under 100. + +exit_weight +----------- + +When a CPU hog task exits, its parent's sleep_avg is reduced by a factor of +exit_weight against the exiting task's sleep_avg. + +interactive_delta +----------------- + +If a task is "interactive" it is reinserted into the active array after it +has expired its timeslice, instead of being inserted into the expired array. +How "interactive" a task must be in order to be deemed interactive is a +function of its nice value. This interactive limit is scaled linearly by nice +value and is offset by the interactive_delta. + +max_sleep_avg +------------- + +max_sleep_avg is the largest value (in ms) stored for a task's running sleep +average. The larger this value, the longer a task needs to sleep to be +considered interactive (maximum interactive bonus is a function of +max_sleep_avg). + +max_timeslice +------------- + +Maximum timeslice, in milliseconds. This is the value given to tasks of the +highest dynamic priority. + +min_timeslice +------------- + +Minimum timeslice, in milliseconds. This is the value given to tasks of the +lowest dynamic priority. Every task gets at least this slice of the processor +per array switch. + +parent_penalty +-------------- + +Percentage of the parent's sleep_avg that it retains across a fork(). +sleep_avg is a running average of the time a process spends sleeping. Tasks +with high sleep_avg values are considered interactive and given a higher +dynamic priority and a larger timeslice. Normally, this value is 100 and thus +task's retain their sleep_avg on fork. If you want to punish interactive +tasks for forking, set this below 100. + +prio_bonus_ratio +---------------- + +Middle percentage of the priority range that tasks can receive as a dynamic +priority. The default value of 25% ensures that nice values at the +extremes are still enforced. For example, nice +19 interactive tasks will +never be able to preempt a nice 0 CPU hog. Setting this higher will increase +the size of the priority range the tasks can receive as a bonus. Setting +this lower will decrease this range, making the interactivity bonus less +apparent and user nice values more applicable. + +starvation_limit +---------------- + +Sufficiently interactive tasks are reinserted into the active array when they +run out of timeslice. Normally, tasks are inserted into the expired array. +Reinserting interactive tasks into the active array allows them to remain +runnable, which is important to interactive performance. This could starve +expired tasks, however, since the interactive task could prevent the array +switch. To prevent starving the tasks on the expired array for too long. the +starvation_limit is the longest (in ms) we will let the expired array starve +at the expense of reinserting interactive tasks back into active. Higher +values here give more preferance to running interactive tasks, at the expense +of expired tasks. Lower values provide more fair scheduling behavior, at the +expense of interactivity. The units are in milliseconds. + +idle_node_rebalance_ratio +------------------------- + +On NUMA machines, we normally rebalance within nodes, but we also rebalance +globally every N idle rebalance ticks, where N = idle_node_rebalance_ratio. + +busy_node_rebalance_ratio +------------------------- + +On NUMA machines, we normally rebalance within nodes, but we also rebalance +globally every N busy rebalance ticks, where N = busy_node_rebalance_ratio. ------------------------------------------------------------------------------ Summary diff -urpN -X /home/fletch/.diff.exclude 105-numameminfo/include/linux/sysctl.h 114-sched_tunables/include/linux/sysctl.h --- 105-numameminfo/include/linux/sysctl.h Tue Sep 2 09:55:56 2003 +++ 114-sched_tunables/include/linux/sysctl.h Tue Sep 2 10:09:31 2003 @@ -61,7 +61,8 @@ enum CTL_DEV=7, /* Devices */ CTL_BUS=8, /* Busses */ CTL_ABI=9, /* Binary emulation */ - CTL_CPU=10 /* CPU stuff (speed scaling, etc) */ + CTL_CPU=10, /* CPU stuff (speed scaling, etc) */ + CTL_SCHED=11, /* scheduler tunables */ }; /* CTL_BUS names: */ @@ -156,6 +157,21 @@ enum VM_MIN_FREE_KBYTES=21, /* Minimum free kilobytes to maintain */ }; +/* Tunable scheduler parameters in /proc/sys/sched/ */ +enum { + SCHED_MIN_TIMESLICE=1, /* minimum process timeslice */ + SCHED_MAX_TIMESLICE=2, /* maximum process timeslice */ + SCHED_CHILD_PENALTY=3, /* penalty on fork to child */ + SCHED_PARENT_PENALTY=4, /* penalty on fork to parent */ + SCHED_EXIT_WEIGHT=5, /* penalty to parent of CPU hog child */ + SCHED_PRIO_BONUS_RATIO=6, /* percent of max prio given as bonus */ + SCHED_INTERACTIVE_DELTA=7, /* delta used to scale interactivity */ + SCHED_MAX_SLEEP_AVG=8, /* maximum sleep avg attainable */ + SCHED_STARVATION_LIMIT=9, /* no re-active if expired is starved */ + SCHED_NODE_THRESHOLD=10, /* NUMA node rebalance threshold */ + SCHED_IDLE_NODE_REBALANCE_RATIO=11, /* how often to global balance */ + SCHED_BUSY_NODE_REBALANCE_RATIO=12, /* how often to global balance */ +}; /* CTL_NET names: */ enum diff -urpN -X /home/fletch/.diff.exclude 105-numameminfo/kernel/sched.c 114-sched_tunables/kernel/sched.c --- 105-numameminfo/kernel/sched.c Tue Sep 2 09:55:57 2003 +++ 114-sched_tunables/kernel/sched.c Tue Sep 2 10:09:31 2003 @@ -66,16 +66,27 @@ * maximum timeslice is 200 msecs. Timeslices get refilled after * they expire. */ -#define MIN_TIMESLICE ( 10 * HZ / 1000) -#define MAX_TIMESLICE (200 * HZ / 1000) -#define CHILD_PENALTY 50 -#define PARENT_PENALTY 100 -#define EXIT_WEIGHT 3 -#define PRIO_BONUS_RATIO 25 -#define INTERACTIVE_DELTA 2 -#define MAX_SLEEP_AVG (10*HZ) -#define STARVATION_LIMIT (10*HZ) -#define NODE_THRESHOLD 125 +int min_timeslice = (10 * HZ) / 1000; +int max_timeslice = (200 * HZ) / 1000; +int child_penalty = 50; +int parent_penalty = 100; +int exit_weight = 3; +int prio_bonus_ratio = 25; +int interactive_delta = 2; +int max_sleep_avg = 10 * HZ; +int starvation_limit = 10 * HZ; +int node_threshold = 125; + +#define MIN_TIMESLICE (min_timeslice) +#define MAX_TIMESLICE (max_timeslice) +#define CHILD_PENALTY (child_penalty) +#define PARENT_PENALTY (parent_penalty) +#define EXIT_WEIGHT (exit_weight) +#define PRIO_BONUS_RATIO (prio_bonus_ratio) +#define INTERACTIVE_DELTA (interactive_delta) +#define MAX_SLEEP_AVG (max_sleep_avg) +#define STARVATION_LIMIT (starvation_limit) +#define NODE_THRESHOLD (node_threshold) /* * If a task is 'interactive' then we reinsert it in the active @@ -875,6 +886,9 @@ static int find_busiest_node(int this_no #endif /* CONFIG_NUMA */ +int idle_node_rebalance_ratio = 10; +int busy_node_rebalance_ratio = 2; + #ifdef CONFIG_SMP /* @@ -1102,8 +1116,8 @@ out: */ #define IDLE_REBALANCE_TICK (HZ/1000 ?: 1) #define BUSY_REBALANCE_TICK (HZ/5 ?: 1) -#define IDLE_NODE_REBALANCE_TICK (IDLE_REBALANCE_TICK * 5) -#define BUSY_NODE_REBALANCE_TICK (BUSY_REBALANCE_TICK * 2) +#define IDLE_NODE_REBALANCE_TICK (IDLE_REBALANCE_TICK * idle_node_rebalance_ratio) +#define BUSY_NODE_REBALANCE_TICK (BUSY_REBALANCE_TICK * busy_node_rebalance_ratio) #ifdef CONFIG_NUMA static void balance_node(runqueue_t *this_rq, int idle, int this_cpu) diff -urpN -X /home/fletch/.diff.exclude 105-numameminfo/kernel/sysctl.c 114-sched_tunables/kernel/sysctl.c --- 105-numameminfo/kernel/sysctl.c Wed Aug 13 20:24:33 2003 +++ 114-sched_tunables/kernel/sysctl.c Tue Sep 2 10:09:31 2003 @@ -58,6 +58,18 @@ extern int cad_pid; extern int pid_max; extern int sysctl_lower_zone_protection; extern int min_free_kbytes; +extern int min_timeslice; +extern int max_timeslice; +extern int child_penalty; +extern int parent_penalty; +extern int exit_weight; +extern int prio_bonus_ratio; +extern int interactive_delta; +extern int max_sleep_avg; +extern int starvation_limit; +extern int node_threshold; +extern int idle_node_rebalance_ratio; +extern int busy_node_rebalance_ratio; /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ static int maxolduid = 65535; @@ -120,6 +132,7 @@ static struct ctl_table_header root_tabl static ctl_table kern_table[]; static ctl_table vm_table[]; +static ctl_table sched_table[]; #ifdef CONFIG_NET extern ctl_table net_table[]; #endif @@ -199,6 +212,12 @@ static ctl_table root_table[] = { .mode = 0555, .child = dev_table, }, + { + .ctl_name = CTL_SCHED, + .procname = "sched", + .mode = 0555, + .child = sched_table, + }, { .ctl_name = 0 } }; @@ -586,6 +605,7 @@ static ctl_table kern_table[] = { /* Constants for minimum and maximum testing in vm_table. We use these as one-element integer vectors. */ static int zero; +static int one = 1; static int one_hundred = 100; @@ -805,6 +825,48 @@ static ctl_table debug_table[] = { static ctl_table dev_table[] = { { .ctl_name = 0 } }; + +static ctl_table sched_table[] = { + {SCHED_MAX_TIMESLICE, "max_timeslice", &max_timeslice, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &one, NULL}, + {SCHED_MIN_TIMESLICE, "min_timeslice", &min_timeslice, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &one, NULL}, + {SCHED_CHILD_PENALTY, "child_penalty", &child_penalty, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_PARENT_PENALTY, "parent_penalty", &parent_penalty, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_EXIT_WEIGHT, "exit_weight", &exit_weight, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_PRIO_BONUS_RATIO, "prio_bonus_ratio", &prio_bonus_ratio, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_INTERACTIVE_DELTA, "interactive_delta", &interactive_delta, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_MAX_SLEEP_AVG, "max_sleep_avg", &max_sleep_avg, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &one, NULL}, + {SCHED_STARVATION_LIMIT, "starvation_limit", &starvation_limit, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_NODE_THRESHOLD, "node_threshold", &node_threshold, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + sysctl_intvec, NULL, &one, NULL}, + {SCHED_IDLE_NODE_REBALANCE_RATIO, "idle_node_rebalance_ratio", + &idle_node_rebalance_ratio, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {SCHED_BUSY_NODE_REBALANCE_RATIO, "busy_node_rebalance_ratio", + &busy_node_rebalance_ratio, + sizeof(int), 0644, NULL, &proc_dointvec_minmax, + &sysctl_intvec, NULL, &zero, NULL}, + {0} +}; extern void init_irq_proc (void);