[PATCH] CKRM [2/8] More accurate account for CPU & IO scheduling

From: Gerrit Huizenga
Date: Thu Feb 24 2005 - 05:13:20 EST

CKRM processor scheduling delay accounting - provides a mechanism
to In addition to counting frequency the total delay in ns is also
recorded. CPU delays are specified as cpu-wait and cpu-run. I/O delays
are recorded for memory and regular I/O. Information is accessible
through /proc/<pid>/delay.

Signed-Off-By: Chandra Seetharaman <sekharan@xxxxxxxxxx>
Signed-Off-By: Hubertus Franke <frankeh@xxxxxxxxxx>
Signed-Off-By: Shailabh Nagar <nagar@xxxxxxxxxx>
Signed-Off-By: Gerrit Huizenga <gh@xxxxxxxxxx>

fs/proc/array.c | 18 +++++++++
fs/proc/base.c | 18 +++++++++
include/linux/sched.h | 86 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/taskdelays.h | 45 +++++++++++++++++++++++
init/Kconfig | 8 ++++
kernel/fork.c | 1
kernel/sched.c | 17 ++++++++
mm/memory.c | 9 +++-
8 files changed, 200 insertions(+), 2 deletions(-)

Index: linux-2.6.11-rc5/fs/proc/array.c
===================================================================
--- linux-2.6.11-rc5.orig/fs/proc/array.c 2005-02-23 20:03:03.000000000 -0800
+++ linux-2.6.11-rc5/fs/proc/array.c 2005-02-24 00:54:56.449085584 -0800
@@ -473,3 +473,21 @@
return sprintf(buffer,"%d %d %d %d %d %d %d\n",
size, resident, shared, text, lib, data, 0);
}
+
+
+int proc_pid_delay(struct task_struct *task, char * buffer)
+{
+ int res;
+
+ res = sprintf(buffer,"%u %llu %llu %u %llu %u %llu\n",
+ (unsigned int) get_delay(task,runs),
+ (uint64_t) get_delay(task,runcpu_total),
+ (uint64_t) get_delay(task,waitcpu_total),
+ (unsigned int) get_delay(task,num_iowaits),
+ (uint64_t) get_delay(task,iowait_total),
+ (unsigned int) get_delay(task,num_memwaits),
+ (uint64_t) get_delay(task,mem_iowait_total)
+ );
+ return res;
+}
+
Index: linux-2.6.11-rc5/fs/proc/base.c
===================================================================
--- linux-2.6.11-rc5.orig/fs/proc/base.c 2005-02-23 20:03:04.000000000 -0800
+++ linux-2.6.11-rc5/fs/proc/base.c 2005-02-24 00:54:56.451085343 -0800
@@ -105,6 +105,10 @@
#ifdef CONFIG_AUDITSYSCALL
PROC_TID_LOGINUID,
#endif
+#ifdef CONFIG_DELAY_ACCT
+ PROC_TID_DELAY_ACCT,
+ PROC_TGID_DELAY_ACCT,
+#endif
PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
PROC_TID_OOM_SCORE,
PROC_TID_OOM_ADJUST,
@@ -137,6 +141,9 @@
#ifdef CONFIG_SECURITY
E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
+#ifdef CONFIG_DELAY_ACCT
+ E(PROC_TGID_DELAY_ACCT,"delay", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_KALLSYMS
E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO),
#endif
@@ -167,6 +174,9 @@
#ifdef CONFIG_SECURITY
E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
+#ifdef CONFIG_DELAY_ACCT
+ E(PROC_TGID_DELAY_ACCT,"delay", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_KALLSYMS
E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO),
#endif
@@ -1476,6 +1486,13 @@
ei->op.proc_read = proc_pid_wchan;
break;
#endif
+#ifdef CONFIG_DELAY_ACCT
+ case PROC_TID_DELAY_ACCT:
+ case PROC_TGID_DELAY_ACCT:
+ inode->i_fop = &proc_info_file_operations;
+ ei->op.proc_read = proc_pid_delay;
+ break;
+#endif
#ifdef CONFIG_SCHEDSTATS
case PROC_TID_SCHEDSTAT:
case PROC_TGID_SCHEDSTAT:
Index: linux-2.6.11-rc5/include/linux/sched.h
===================================================================
--- linux-2.6.11-rc5.orig/include/linux/sched.h 2005-02-23 20:02:21.000000000 -0800
+++ linux-2.6.11-rc5/include/linux/sched.h 2005-02-24 00:54:56.482081606 -0800
@@ -32,6 +32,7 @@
#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
+#include <linux/taskdelays.h>

struct exec_domain;

@@ -685,6 +686,9 @@
struct mempolicy *mempolicy;
short il_next;
#endif
+#ifdef CONFIG_DELAY_ACCT
+ struct task_delay_info delays;
+#endif
};

static inline pid_t process_group(struct task_struct *tsk)
@@ -980,6 +984,9 @@
extern void set_task_comm(struct task_struct *tsk, char *from);
extern void get_task_comm(char *to, struct task_struct *tsk);

+#define PF_MEMIO 0x00400000 /* I am potentially doing I/O for mem */
+#define PF_IOWAIT 0x00800000 /* I am waiting on disk I/O */
+
#ifdef CONFIG_SMP
extern void wait_task_inactive(task_t * p);
#else
@@ -1214,6 +1221,88 @@
return 0;
}
#endif /* CONFIG_PM */
+
+/* API for registering delay info */
+#ifdef CONFIG_DELAY_ACCT
+
+#define test_delay_flag(tsk,flg) ((tsk)->flags & (flg))
+#define set_delay_flag(tsk,flg) ((tsk)->flags |= (flg))
+#define clear_delay_flag(tsk,flg) ((tsk)->flags &= ~(flg))
+
+#define def_delay_var(var) unsigned long long var
+#define get_delay(tsk,field) ((tsk)->delays.field)
+
+#define start_delay(var) ((var) = sched_clock())
+#define start_delay_set(var,flg) (set_delay_flag(current,flg),(var) = \
+ sched_clock())
+
+#define inc_delay(tsk,field) (((tsk)->delays.field)++)
+
+/* because of hardware timer drifts in SMPs and task continue on different cpu
+ * then where the start_ts was taken there is a possibility that
+ * end_ts < start_ts by some usecs. In this case we ignore the diff
+ * and add nothing to the total.
+ */
+#ifdef CONFIG_SMP
+#define test_ts_integrity(start_ts,end_ts) (likely((end_ts) > (start_ts)))
+#else
+#define test_ts_integrity(start_ts,end_ts) (1)
+#endif
+
+#define add_delay_ts(tsk,field,start_ts,end_ts) \
+ do { if (test_ts_integrity(start_ts,end_ts)) (tsk)->delays.field += ((end_ts)-(start_ts)); } while (0)
+
+#define add_delay_clear(tsk,field,start_ts,flg) \
+ do { \
+ unsigned long long now = sched_clock(); \
+ add_delay_ts(tsk,field,start_ts,now); \
+ clear_delay_flag(tsk,flg); \
+ } while (0)
+
+static inline void add_io_delay(unsigned long long dstart)
+{
+ struct task_struct * tsk = current;
+ unsigned long long now = sched_clock();
+ unsigned long long val;
+
+ if (test_ts_integrity(dstart,now))
+ val = now - dstart;
+ else
+ val = 0;
+ if (test_delay_flag(tsk,PF_MEMIO)) {
+ tsk->delays.mem_iowait_total += val;
+ tsk->delays.num_memwaits++;
+ } else {
+ tsk->delays.iowait_total += val;
+ tsk->delays.num_iowaits++;
+ }
+ clear_delay_flag(tsk,PF_IOWAIT);
+}
+
+inline static void init_delays(struct task_struct *tsk)
+{
+ memset((void*)&tsk->delays,0,sizeof(tsk->delays));
+}
+
+#else
+
+#define test_delay_flag(tsk,flg) (0)
+#define set_delay_flag(tsk,flg) do { } while (0)
+#define clear_delay_flag(tsk,flg) do { } while (0)
+
+#define def_delay_var(var)
+#define get_delay(tsk,field) (0)
+
+#define start_delay(var) do { } while (0)
+#define start_delay_set(var,flg) do { } while (0)
+
+#define inc_delay(tsk,field) do { } while (0)
+#define add_delay_ts(tsk,field,start_ts,now) do { } while (0)
+#define add_delay_clear(tsk,field,start_ts,flg) do { } while (0)
+#define add_io_delay(dstart) do { } while (0)
+#define init_delays(tsk) do { } while (0)
+#endif
+
#endif /* __KERNEL__ */

#endif
Index: linux-2.6.11-rc5/include/linux/taskdelays.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.11-rc5/include/linux/taskdelays.h 2005-02-24 00:54:56.483081485 -0800
@@ -0,0 +1,35 @@
+/* taskdelays.h - for delay accounting
+ *
+ * Copyright (C) Hubertus Franke, IBM Corp. 2003, 2004
+ *
+ * Has the data structure for delay counting.
+ *
+ * Latest version, more details at http://ckrm.sf.net
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#ifndef _LINUX_TASKDELAYS_H
+#define _LINUX_TASKDELAYS_H
+
+#include <linux/config.h>
+#include <linux/types.h>
+
+struct task_delay_info {
+ /* delay statistics in usecs */
+ uint64_t waitcpu_total;
+ uint64_t runcpu_total;
+ uint64_t iowait_total;
+ uint64_t mem_iowait_total;
+ uint32_t runs;
+ uint32_t num_iowaits;
+ uint32_t num_memwaits;
+};
+
+#endif /* _LINUX_TASKDELAYS_H */
Index: linux-2.6.11-rc5/init/Kconfig
===================================================================
--- linux-2.6.11-rc5.orig/init/Kconfig 2005-02-24 00:54:50.538798203 -0800
+++ linux-2.6.11-rc5/init/Kconfig 2005-02-24 00:54:56.554072926 -0800
@@ -262,6 +262,14 @@
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.

+config DELAY_ACCT
+ bool "Enable delay accounting (EXPERIMENTAL)"
+ help
+ In addition to counting frequency the total delay in ns is also
+ recorded. CPU delays are specified as cpu-wait and cpu-run.
+ I/O delays are recorded for memory and regular I/O.
+ Information is accessible through /proc/<pid>/delay.
+
config KALLSYMS
bool "Load all symbols for debugging/kksymoops" if EMBEDDED
default y
Index: linux-2.6.11-rc5/kernel/fork.c
===================================================================
--- linux-2.6.11-rc5.orig/kernel/fork.c 2005-02-24 00:54:50.647785063 -0800
+++ linux-2.6.11-rc5/kernel/fork.c 2005-02-24 00:54:56.555072805 -0800
@@ -849,6 +849,7 @@
if (p->binfmt && !try_module_get(p->binfmt->module))
goto bad_fork_cleanup_put_domain;

+ init_delays(p);
p->did_exec = 0;
copy_flags(clone_flags, p);
p->pid = pid;
Index: linux-2.6.11-rc5/kernel/sched.c
===================================================================
--- linux-2.6.11-rc5.orig/kernel/sched.c 2005-02-23 20:03:10.000000000 -0800
+++ linux-2.6.11-rc5/kernel/sched.c 2005-02-24 00:54:56.572070756 -0800
@@ -288,6 +288,8 @@
#define task_rq(p) cpu_rq(task_cpu(p))
#define cpu_curr(cpu) (cpu_rq(cpu)->curr)

+#define task_is_running(p) (this_rq() == task_rq(p))
+
/*
* Default context-switch locking:
*/
@@ -2799,6 +2801,7 @@
clear_tsk_need_resched(prev);
rcu_qsctr_inc(task_cpu(prev));

+ add_delay_ts(prev, runcpu_total, prev->timestamp, now);
prev->sleep_avg -= run_time;
if ((long)prev->sleep_avg <= 0)
prev->sleep_avg = 0;
@@ -2806,6 +2809,8 @@

sched_info_switch(prev, next);
if (likely(prev != next)) {
+ add_delay_ts(next, waitcpu_total, next->timestamp, now);
+ inc_delay(next, runs);
next->timestamp = now;
rq->nr_switches++;
rq->curr = next;
@@ -3849,9 +3854,12 @@
{
struct runqueue *rq = &per_cpu(runqueues, _smp_processor_id());

+ def_delay_var(dstart);
+ start_delay_set(dstart, PF_IOWAIT);
atomic_inc(&rq->nr_iowait);
schedule();
atomic_dec(&rq->nr_iowait);
+ add_io_delay(dstart);
}

EXPORT_SYMBOL(io_schedule);
@@ -3860,10 +3868,13 @@
{
struct runqueue *rq = &per_cpu(runqueues, _smp_processor_id());
long ret;
+ def_delay_var(dstart);

+ start_delay_set(dstart,PF_IOWAIT);
atomic_inc(&rq->nr_iowait);
ret = schedule_timeout(timeout);
atomic_dec(&rq->nr_iowait);
+ add_io_delay(dstart);
return ret;
}

@@ -5051,3 +5062,12 @@
}

#endif /* CONFIG_MAGIC_SYSRQ */
+
+#ifdef CONFIG_DELAY_ACCT
+int task_running_sys(struct task_struct *p)
+{
+ return task_is_running(p);
+}
+EXPORT_SYMBOL_GPL(task_running_sys);
+#endif
+
Index: linux-2.6.11-rc5/mm/memory.c
===================================================================
--- linux-2.6.11-rc5.orig/mm/memory.c 2005-02-23 20:02:38.000000000 -0800
+++ linux-2.6.11-rc5/mm/memory.c 2005-02-24 00:54:56.589068706 -0800
@@ -2065,6 +2065,7 @@
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
+ int rc;

__set_current_state(TASK_RUNNING);

@@ -2078,6 +2079,9 @@
* and the SMP-safe atomic PTE updates.
*/
pgd = pgd_offset(mm, address);
+
+ set_delay_flag(current, PF_MEMIO);
+
spin_lock(&mm->page_table_lock);

pud = pud_alloc(mm, pgd, address);
@@ -2092,10 +2096,13 @@
if (!pte)
goto oom;

- return handle_pte_fault(mm, vma, address, write_access, pte, pmd);
+ rc = handle_pte_fault(mm, vma, address, write_access, pte, pmd);
+ clear_delay_flag(current, PF_MEMIO);
+ return rc;

oom:
spin_unlock(&mm->page_table_lock);
+ clear_delay_flag(current, PF_MEMIO);
return VM_FAULT_OOM;
}

Index: linux-2.6.11-rc5/fs/proc/internal.h
===================================================================
--- linux-2.6.11-rc5.orig/fs/proc/internal.h 2005-02-23 20:02:21.000000000 -0800
+++ linux-2.6.11-rc5/fs/proc/internal.h 2005-02-24 00:54:56.590068586 -0800
@@ -36,6 +36,7 @@
extern int proc_tgid_stat(struct task_struct *, char *);
extern int proc_pid_status(struct task_struct *, char *);
extern int proc_pid_statm(struct task_struct *, char *);
+extern int proc_pid_delay(struct task_struct *, char*);

static inline struct task_struct *proc_task(struct inode *inode)
{
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/