Subject: [PATCH] Performance Stats: Kernel patch

From: Maxim Uvarov <[email-masked]>
Date: Thu, 10 May 2007 12:39:50 +0000

Patch makes available to the user the following
task and process performance statistics:
	* Involuntary Context Switches (task_struct->nivcsw)
	* Voluntary Context Switches (task_struct->nvcsw)
	* Number of system calls (added new counter
	  thread_info->sysall_count)
	           
Statistics information is available from:
        1. taskstats interface (Documentation/accounting/)
	2. /proc/PID/status (task only).

This data is useful for detecting hyperactivity
patterns between processes.

Signed-off-by: Maxim Uvarov <[email-masked]>

Changing nvcsw to voluntary_ctxt_switches.

Signed-off-by: Maxim Uvarov <[email-masked]>                                                                                  
---

 Documentation/accounting/getdelays.c          |   20 ++++++++++++++++++--
 Documentation/accounting/taskstats-struct.txt |    7 +++++++
 arch/i386/kernel/asm-offsets.c                |    1 +
 arch/i386/kernel/entry.S                      |    3 +++
 arch/powerpc/kernel/asm-offsets.c             |    2 ++
 arch/powerpc/kernel/entry_32.S                |    5 +++++
 arch/powerpc/kernel/entry_64.S                |    5 +++++
 arch/x86_64/kernel/asm-offsets.c              |    1 +
 arch/x86_64/kernel/entry.S                    |    3 +++
 fs/proc/array.c                               |   14 ++++++++++++++
 include/asm-i386/thread_info.h                |    1 +
 include/asm-powerpc/thread_info.h             |    1 +
 include/asm-x86_64/thread_info.h              |    1 +
 include/linux/taskstats.h                     |    6 +++++-
 kernel/fork.c                                 |    3 +++
 kernel/taskstats.c                            |    6 ++++++
 16 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c
index e9126e7..1be7d65 100644
--- a/Documentation/accounting/getdelays.c
+++ b/Documentation/accounting/getdelays.c
@@ -49,6 +49,7 @@ char name[100];
 int dbg;
 int print_delays;
 int print_io_accounting;
+int print_task_stats;
 __u64 stime, utime;
 
 #define PRINTF(fmt, arg...) {			\
@@ -187,7 +188,7 @@ void print_delayacct(struct taskstats *t)
 	       "IO    %15s%15s\n"
 	       "      %15llu%15llu\n"
 	       "MEM   %15s%15s\n"
-	       "      %15llu%15llu\n\n",
+	       "      %15llu%15llu\n"
 	       "count", "real total", "virtual total", "delay total",
 	       t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
 	       t->cpu_delay_total,
@@ -196,6 +197,15 @@ void print_delayacct(struct taskstats *t)
 	       "count", "delay total", t->swapin_count, t->swapin_delay_total);
 }
 
+void print_taskstats(struct taskstats *t)
+{
+	printf("\n\nTask  %15s%15s%15s\n"
+	       "      %15lu%15lu%15lu\n",
+	       "syscalls", "voluntary", "nonvoluntary",
+	       t->syscall_counter, t->nvcsw, t->nivcsw);
+
+}
+
 void print_ioacct(struct taskstats *t)
 {
 	printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
@@ -227,7 +237,7 @@ int main(int argc, char *argv[])
 	struct msgtemplate msg;
 
 	while (1) {
-		c = getopt(argc, argv, "diw:r:m:t:p:v:l");
+		c = getopt(argc, argv, "qdiw:r:m:t:p:v:l");
 		if (c < 0)
 			break;
 
@@ -240,6 +250,10 @@ int main(int argc, char *argv[])
 			printf("printing IO accounting\n");
 			print_io_accounting = 1;
 			break;
+		case 'q':
+			printf("printing task/process stasistics:\n");
+			print_task_stats = 1;
+			break;
 		case 'w':
 			strncpy(logfile, optarg, MAX_FILENAME);
 			printf("write to file %s\n", logfile);
@@ -381,6 +395,8 @@ int main(int argc, char *argv[])
 							print_delayacct((struct taskstats *) NLA_DATA(na));
 						if (print_io_accounting)
 							print_ioacct((struct taskstats *) NLA_DATA(na));
+						if (print_task_stats)
+							print_taskstats((struct taskstats *) NLA_DATA(na));
 						if (fd) {
 							if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
 								err(1,"write error\n");
diff --git a/Documentation/accounting/taskstats-struct.txt b/Documentation/accounting/taskstats-struct.txt
index 661c797..5dac173 100644
--- a/Documentation/accounting/taskstats-struct.txt
+++ b/Documentation/accounting/taskstats-struct.txt
@@ -22,6 +22,8 @@ There are three different groups of fields in the struct taskstats:
     /* Extended accounting fields end */
     Their values are collected if CONFIG_TASK_XACCT is set.
 
+4) Per-task and per-thread statistics
+
 Future extension should add fields to the end of the taskstats struct, and
 should not change the relative position of each field within the struct.
 
@@ -158,4 +160,9 @@ struct taskstats {
 
 	/* Extended accounting fields end */
 
+4) Per-task and per-thread statiscits
+	__u32	syscall_counter;	/* Syscall counter */
+	__u32	nvcsw;			/* Context voluntary switch counter */
+	__u32	nivcsw;			/* Context involuntary switch counter */
+
 }
diff --git a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c
index 1b2f3cd..4ad49d2 100644
--- a/arch/i386/kernel/asm-offsets.c
+++ b/arch/i386/kernel/asm-offsets.c
@@ -56,6 +56,7 @@ void foo(void)
 	OFFSET(TI_addr_limit, thread_info, addr_limit);
 	OFFSET(TI_restart_block, thread_info, restart_block);
 	OFFSET(TI_sysenter_return, thread_info, sysenter_return);
+	OFFSET(TI_syscall_count, thread_info, syscall_count);
 	BLANK();
 
 	OFFSET(GDS_size, Xgt_desc_struct, size);
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 5e47683..836961f 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -332,6 +332,9 @@ sysenter_past_esp:
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
 
+#ifdef CONFIG_TASKSTATS
+	incl	TI_syscall_count(%ebp)	# Increment syscalls counter
+#endif
 	/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
 	testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
 	jnz syscall_trace_entry
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 030d300..b640039 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -94,6 +94,8 @@ int main(void)
 	DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags));
 	DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
 	DEFINE(TI_TASK, offsetof(struct thread_info, task));
+	DEFINE(TI_SYSCALL_COUNT, offsetof(struct thread_info, syscall_count));
+
 #ifdef CONFIG_PPC32
 	DEFINE(TI_EXECDOMAIN, offsetof(struct thread_info, exec_domain));
 	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index c03e829..5d919e4 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -202,6 +202,11 @@ _GLOBAL(DoSyscall)
 	bl	do_show_syscall
 #endif /* SHOW_SYSCALLS */
 	rlwinm	r10,r1,0,0,(31-THREAD_SHIFT)	/* current_thread_info() */
+#ifdef CONFIG_TASKSTATS 
+	lwz r11,TI_SYSC_CNT(r10)
+	addi r11,r11,1
+	stw r11,TI_SYSC_CNT(r10)
+#endif
 	lwz	r11,TI_FLAGS(r10)
 	andi.	r11,r11,_TIF_SYSCALL_T_OR_A
 	bne-	syscall_dotrace
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 2551c08..5907f76 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -115,6 +115,11 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
 	addi	r9,r1,STACK_FRAME_OVERHEAD
 #endif
 	clrrdi	r11,r1,THREAD_SHIFT
+#ifdef CONFIG_TASKSTATS
+	ld r10,TI_SYSCALL_COUNT(r11)
+	addi r10,r10,1
+	std r10,TI_SYSCALL_COUNT(r11)
+#endif
 	ld	r10,TI_FLAGS(r11)
 	andi.	r11,r10,_TIF_SYSCALL_T_OR_A
 	bne-	syscall_dotrace
diff --git a/arch/x86_64/kernel/asm-offsets.c b/arch/x86_64/kernel/asm-offsets.c
index 96687e2..da57356 100644
--- a/arch/x86_64/kernel/asm-offsets.c
+++ b/arch/x86_64/kernel/asm-offsets.c
@@ -35,6 +35,7 @@ int main(void)
 	ENTRY(addr_limit);
 	ENTRY(preempt_count);
 	ENTRY(status);
+	ENTRY(syscall_count);
 	BLANK();
 #undef ENTRY
 #define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry))
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 9f5dac6..af40ead 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -229,6 +229,9 @@ ENTRY(system_call)
 	movq  %rcx,RIP-ARGOFFSET(%rsp)
 	CFI_REL_OFFSET rip,RIP-ARGOFFSET
 	GET_THREAD_INFO(%rcx)
+#ifdef CONFIG_TASKSTATS
+	addq $1, threadinfo_syscall_count(%rcx)   # Increment syscalls counter
+#endif
 	testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%rcx)
 	jnz tracesys
 	cmpq $__NR_syscall_max,%rax
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 70e4fab..c805c08 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -290,6 +290,19 @@ static inline char *task_cap(struct task_struct *p, char *buffer)
 			    cap_t(p->cap_permitted),
 			    cap_t(p->cap_effective));
 }
+static inline char *task_perf(struct task_struct *p, char *buffer)
+{
+	/* Syscall counter adds 1 line overhead on each syscall execution
+	 * in entry.S, so probably it is the leave this stuff under ifdefs.
+	 */
+#ifdef CONFIG_TASKSTATS
+	buffer += sprintf(buffer, "Syscalls:\t%lu\n", p->thread_info->syscall_count);
+#endif
+	return buffer + sprintf(buffer, "voluntary_ctxt_switches:\t%lu\n"
+			    "nonvoluntary_ctxt_switches:\t%lu\n",
+			    p->nvcsw,
+			    p->nivcsw);
+}
 
 int proc_pid_status(struct task_struct *task, char * buffer)
 {
@@ -309,6 +322,7 @@ int proc_pid_status(struct task_struct *task, char * buffer)
 #if defined(CONFIG_S390)
 	buffer = task_show_regs(task, buffer);
 #endif
+	buffer = task_perf(task, buffer);
 	return buffer - orig;
 }
 
diff --git a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
index 4b187bb..bccfd6a 100644
--- a/include/asm-i386/thread_info.h
+++ b/include/asm-i386/thread_info.h
@@ -33,6 +33,7 @@ struct thread_info {
 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */

+	unsigned long		syscall_count;	/* Syscall counter */
 	mm_segment_t		addr_limit;	/* thread address space:
 					 	   0-0xBFFFFFFF for user-thead
 						   0-0xFFFFFFFF for kernel-thread
diff --git a/include/asm-powerpc/thread_info.h b/include/asm-powerpc/thread_info.h
index 3f32ca8..5306ac2 100644
--- a/include/asm-powerpc/thread_info.h
+++ b/include/asm-powerpc/thread_info.h
@@ -35,6 +35,7 @@ struct thread_info {
 	int		cpu;			/* cpu we're on */
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
+	unsigned long	syscall_count;		/* Syscall counter */
 	struct restart_block restart_block;
 	unsigned long	local_flags;		/* private flags for thread */
 
diff --git a/include/asm-x86_64/thread_info.h b/include/asm-x86_64/thread_info.h
index 74a6c74..e53022d 100644
--- a/include/asm-x86_64/thread_info.h
+++ b/include/asm-x86_64/thread_info.h
@@ -31,6 +31,7 @@ struct thread_info {
 	__u32			cpu;		/* current CPU */
 	int 			preempt_count;	/* 0 => preemptable, <0 => BUG */
 
+	unsigned long		syscall_count;	/* Syscall counter */
 	mm_segment_t		addr_limit;	
 	struct restart_block    restart_block;
 };
diff --git a/include/linux/taskstats.h b/include/linux/taskstats.h
index 3fced47..e3341b6 100644
--- a/include/linux/taskstats.h
+++ b/include/linux/taskstats.h
@@ -31,7 +31,7 @@
  */

-#define TASKSTATS_VERSION	3
+#define TASKSTATS_VERSION	4
 #define TS_COMM_LEN		32	/* should be >= TASK_COMM_LEN
 					 * in linux/sched.h */
 
@@ -141,6 +141,10 @@ struct taskstats {
 	__u64	write_syscalls;		/* write syscalls */
 	/* Extended accounting fields end */
 
+	__u32  syscall_counter;   /* Syscall counter */
+	__u32  nvcsw;
+	__u32  nivcsw;
+
 #define TASKSTATS_HAS_IO_ACCOUNTING
 	/* Per-task storage I/O accounting starts */
 	__u64	read_bytes;		/* bytes of read I/O */
diff --git a/kernel/fork.c b/kernel/fork.c
index fc723e5..5213738 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1042,6 +1042,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->wchar = 0;		/* I/O counter: bytes written */
 	p->syscr = 0;		/* I/O counter: read syscalls */
 	p->syscw = 0;		/* I/O counter: write syscalls */
+#ifdef CONFIG_TASKSTATS
+	p->thread_info->syscall_count = 0; /* Syscall counter: total numbers of syscalls */
+#endif
 	task_io_accounting_init(p);
 	acct_clear_integrals(p);
 
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 4c3476f..d7bf33f 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -196,6 +196,9 @@ static int fill_pid(pid_t pid, struct task_struct *tsk,
 
 	/* fill in basic acct fields */
 	stats->version = TASKSTATS_VERSION;
+	stats->syscall_counter = tsk->thread_info->syscall_count;
+	stats->nvcsw = tsk->nvcsw;
+	stats->nivcsw = tsk->nivcsw;
 	bacct_add_tsk(stats, tsk);
 
 	/* fill in extended acct fields */
@@ -242,6 +245,9 @@ static int fill_tgid(pid_t tgid, struct task_struct *first,
 		 */
 		delayacct_add_tsk(stats, tsk);
 
+		stats->syscall_counter += tsk->thread_info->syscall_count;
+		stats->nvcsw += tsk->nvcsw;
+		stats->nivcsw += tsk->nivcsw;
 	} while_each_thread(first, tsk);
 
 	unlock_task_sighand(first, &flags);