From 5926c50b83b626991c8c38efbca2020ee96b215f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 16 Jul 2007 09:46:30 +0200 Subject: [PATCH] sched: remove dead code from task_stime() Alexey Dobriyan noticed that task_stime() contains a piece of dead code. (which is a remnant of earlier versions of this code) Remove that code. Signed-off-by: Ingo Molnar --- fs/proc/array.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index 98e78e2f18d..c6977796faf 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -332,7 +332,7 @@ static clock_t task_utime(struct task_struct *p) static clock_t task_stime(struct task_struct *p) { - clock_t stime = cputime_to_clock_t(p->stime); + clock_t stime; /* * Use CFS's precise accounting. (we subtract utime from -- cgit v1.2.3 From f9153ee6c71cb9ab38de3b8ed66b1c3fa27c3f7d Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 16 Jul 2007 09:46:30 +0200 Subject: [PATCH] sched: improve weight-array comments improve the comments around the wmult array (which controls the weight of niced tasks). Clarify that to achieve a 10% difference in CPU utilization, a weight multiplier of 1.25 has to be used. Signed-off-by: Ingo Molnar --- kernel/sched.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched.c b/kernel/sched.c index 3332bbb5d5c..a7284bc79cd 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -736,7 +736,9 @@ static void update_curr_load(struct rq *rq, u64 now) * * The "10% effect" is relative and cumulative: from _any_ nice level, * if you go up 1 level, it's -10% CPU usage, if you go down 1 level - * it's +10% CPU usage. + * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. + * If a task goes up by ~10% and another task goes down by ~10% then + * the relative distance between them is ~25%.) */ static const int prio_to_weight[40] = { /* -20 */ 88818, 71054, 56843, 45475, 36380, 29104, 23283, 18626, 14901, 11921, -- cgit v1.2.3 From 5714d2de93fbb156c5e45fb101a2b4f0cae8fbb7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 16 Jul 2007 09:46:31 +0200 Subject: [PATCH] sched: document prio_to_wmult[] document prio_to_wmult[]. Signed-off-by: Ingo Molnar --- kernel/sched.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index a7284bc79cd..90d22b72cf8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -748,6 +748,13 @@ static const int prio_to_weight[40] = { /* 10 */ 110, 87, 70, 56, 45, 36, 29, 23, 18, 15, }; +/* + * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. + * + * In cases where the weight does not change often, we can use the + * precalculated inverse to speed up arithmetics by turning divisions + * into multiplications: + */ static const u32 prio_to_wmult[40] = { 48356, 60446, 75558, 94446, 118058, 147573, 184467, 230589, 288233, 360285, 450347, -- cgit v1.2.3 From e4af30be8fd0bed0e8f96e4e1ebd546a3dfa8f2b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 16 Jul 2007 09:46:31 +0200 Subject: [PATCH] sched: prettify prio_to_wmult[] prettify the prio_to_wmult[] array. (this could have saved us from the typos) Signed-off-by: Ingo Molnar --- kernel/sched.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 90d22b72cf8..1c8076676eb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -756,14 +756,14 @@ static const int prio_to_weight[40] = { * into multiplications: */ static const u32 prio_to_wmult[40] = { - 48356, 60446, 75558, 94446, 118058, 147573, - 184467, 230589, 288233, 360285, 450347, - 562979, 703746, 879575, 1099582, 1374389, - 1717986, 2147483, 2684354, 3355443, 4194304, - 5244160, 6557201, 8196502, 10250518, 12782640, - 16025997, 19976592, 24970740, 31350126, 39045157, - 49367440, 61356675, 76695844, 95443717, 119304647, - 148102320, 186737708, 238609294, 286331153, +/* -20 */ 48356, 60446, 75558, 94446, 118058, +/* -15 */ 147573, 184467, 230589, 288233, 360285, +/* -10 */ 450347, 562979, 703746, 879575, 1099582, +/* -5 */ 1374389, 1717986, 2147483, 2684354, 3355443, +/* 0 */ 4194304, 5244160, 6557201, 8196502, 10250518, +/* 5 */ 12782640, 16025997, 19976592, 24970740, 31350126, +/* 10 */ 39045157, 49367440, 61356675, 76695844, 95443717, +/* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, }; static inline void -- cgit v1.2.3 From 8ea02606681beb41568c62ba060bdf51fc9ba14e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 16 Jul 2007 09:46:31 +0200 Subject: [PATCH] sched: fix up fs/proc/array.c whitespace problems while changing task_stime() i noticed a whitespace style problem in array.c - fix it. While at it, fix all the other style problems too, most of them in the scheduler-stats related portions of array.c. There is no change in functionality: text data bss dec hex filename 4356 28 0 4384 1120 array.o-before 4356 28 0 4384 1120 array.o-after Signed-off-by: Ingo Molnar --- fs/proc/array.c | 51 +++++++++++++++++++++++++-------------------------- 1 file changed, 25 insertions(+), 26 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index c6977796faf..4cb81776a7f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -62,6 +62,8 @@ #include #include #include +#include +#include #include #include #include @@ -76,9 +78,7 @@ #include #include -#include #include -#include #include #include "internal.h" @@ -87,10 +87,10 @@ do { memcpy(buffer, string, strlen(string)); \ buffer += strlen(string); } while (0) -static inline char * task_name(struct task_struct *p, char * buf) +static inline char *task_name(struct task_struct *p, char *buf) { int i; - char * name; + char *name; char tcomm[sizeof(p->comm)]; get_task_comm(tcomm, p); @@ -138,7 +138,7 @@ static const char *task_state_array[] = { "X (dead)" /* 32 */ }; -static inline const char * get_task_state(struct task_struct *tsk) +static inline const char *get_task_state(struct task_struct *tsk) { unsigned int state = (tsk->state & (TASK_RUNNING | TASK_INTERRUPTIBLE | @@ -156,7 +156,7 @@ static inline const char * get_task_state(struct task_struct *tsk) return *p; } -static inline char * task_state(struct task_struct *p, char *buffer) +static inline char *task_state(struct task_struct *p, char *buffer) { struct group_info *group_info; int g; @@ -172,8 +172,8 @@ static inline char * task_state(struct task_struct *p, char *buffer) "Uid:\t%d\t%d\t%d\t%d\n" "Gid:\t%d\t%d\t%d\t%d\n", get_task_state(p), - p->tgid, p->pid, - pid_alive(p) ? rcu_dereference(p->real_parent)->tgid : 0, + p->tgid, p->pid, + pid_alive(p) ? rcu_dereference(p->real_parent)->tgid : 0, pid_alive(p) && p->ptrace ? rcu_dereference(p->parent)->pid : 0, p->uid, p->euid, p->suid, p->fsuid, p->gid, p->egid, p->sgid, p->fsgid); @@ -191,15 +191,15 @@ static inline char * task_state(struct task_struct *p, char *buffer) get_group_info(group_info); task_unlock(p); - for (g = 0; g < min(group_info->ngroups,NGROUPS_SMALL); g++) - buffer += sprintf(buffer, "%d ", GROUP_AT(group_info,g)); + for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++) + buffer += sprintf(buffer, "%d ", GROUP_AT(group_info, g)); put_group_info(group_info); buffer += sprintf(buffer, "\n"); return buffer; } -static char * render_sigset_t(const char *header, sigset_t *set, char *buffer) +static char *render_sigset_t(const char *header, sigset_t *set, char *buffer) { int i, len; @@ -239,7 +239,7 @@ static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign, } } -static inline char * task_sig(struct task_struct *p, char *buffer) +static inline char *task_sig(struct task_struct *p, char *buffer) { unsigned long flags; sigset_t pending, shpending, blocked, ignored, caught; @@ -289,14 +289,14 @@ static inline char *task_cap(struct task_struct *p, char *buffer) cap_t(p->cap_effective)); } -int proc_pid_status(struct task_struct *task, char * buffer) +int proc_pid_status(struct task_struct *task, char *buffer) { - char * orig = buffer; + char *orig = buffer; struct mm_struct *mm = get_task_mm(task); buffer = task_name(task, buffer); buffer = task_state(task, buffer); - + if (mm) { buffer = task_mem(mm, buffer); mmput(mm); @@ -344,8 +344,7 @@ static clock_t task_stime(struct task_struct *p) return stime; } - -static int do_task_stat(struct task_struct *task, char * buffer, int whole) +static int do_task_stat(struct task_struct *task, char *buffer, int whole) { unsigned long vsize, eip, esp, wchan = ~0UL; long priority, nice; @@ -353,7 +352,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) sigset_t sigign, sigcatch; char state; int res; - pid_t ppid = 0, pgid = -1, sid = -1; + pid_t ppid = 0, pgid = -1, sid = -1; int num_threads = 0; struct mm_struct *mm; unsigned long long start_time; @@ -424,7 +423,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) } rcu_read_unlock(); - if (!whole || num_threads<2) + if (!whole || num_threads < 2) wchan = get_wchan(task); if (!whole) { min_flt = task->min_flt; @@ -445,7 +444,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) /* convert nsec -> ticks */ start_time = nsec_to_clock_t(start_time); - res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %u %lu \ + res = sprintf(buffer, "%d (%s) %c %d %d %d %d %d %u %lu \ %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \ %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu\n", task->pid, @@ -471,7 +470,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) start_time, vsize, mm ? get_mm_rss(mm) : 0, - rsslim, + rsslim, mm ? mm->start_code : 0, mm ? mm->end_code : 0, mm ? mm->start_stack : 0, @@ -493,17 +492,17 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) task->rt_priority, task->policy, (unsigned long long)delayacct_blkio_ticks(task)); - if(mm) + if (mm) mmput(mm); return res; } -int proc_tid_stat(struct task_struct *task, char * buffer) +int proc_tid_stat(struct task_struct *task, char *buffer) { return do_task_stat(task, buffer, 0); } -int proc_tgid_stat(struct task_struct *task, char * buffer) +int proc_tgid_stat(struct task_struct *task, char *buffer) { return do_task_stat(task, buffer, 1); } @@ -512,12 +511,12 @@ int proc_pid_statm(struct task_struct *task, char *buffer) { int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0; struct mm_struct *mm = get_task_mm(task); - + if (mm) { size = task_statm(mm, &shared, &text, &data, &resident); mmput(mm); } - return sprintf(buffer,"%d %d %d %d %d %d %d\n", + return sprintf(buffer, "%d %d %d %d %d %d %d\n", size, resident, shared, text, lib, data, 0); } -- cgit v1.2.3