lkml.org 
[lkml]   [2005]   [Dec]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[RFC][PATCH] Add timestamp to process event connector message
From
Date
        This patch adds a timestamp field to the events sent via the process
event connector. The timestamp allows listeners to accurately account the
duration(s) between a process' events and offers strong means with which to
determine the order of events while also avoiding the addition of per-task data.

This alters the size and layout of the event structure and hence would
break compatibility if process events connector as it stands in 2.6.15-rc5 were
released as a mainline kernel.

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>

--

Index: linux-2.6.15-rc5/drivers/connector/cn_proc.c
===================================================================
--- linux-2.6.15-rc5.orig/drivers/connector/cn_proc.c
+++ linux-2.6.15-rc5/drivers/connector/cn_proc.c
@@ -42,10 +42,31 @@ static inline void get_seq(__u32 *ts, in
*ts = get_cpu_var(proc_event_counts)++;
*cpu = smp_processor_id();
put_cpu_var(proc_event_counts);
}

+static inline void get_timestamp(struct timespec *ts)
+{
+ unsigned int seq;
+ struct timespec wall2mono;
+
+ /* synchronize with settimeofday() changes */
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ getnstimeofday(ts);
+ wall2mono = wall_to_monotonic;
+ } while(read_seqretry(&xtime_lock, seq));
+
+ /* adjust to monotonicaly-increasing values */
+ ts += wall2mono.tv_sec;
+ ts += wall2mono.tv_nsec;
+ while ((ts->tv_nsec - NSEC_PER_SEC) >= 0) {
+ ts->tv_nsec -= NSEC_PER_SEC;
+ ts->tv_sec++;
+ }
+}
+
void proc_fork_connector(struct task_struct *task)
{
struct cn_msg *msg;
struct proc_event *ev;
__u8 buffer[CN_PROC_MSG_SIZE];
@@ -54,10 +75,11 @@ void proc_fork_connector(struct task_str
return;

msg = (struct cn_msg*)buffer;
ev = (struct proc_event*)msg->data;
get_seq(&msg->seq, &ev->cpu);
+ get_timestamp(&ev->timestamp);
ev->what = PROC_EVENT_FORK;
ev->event_data.fork.parent_pid = task->real_parent->pid;
ev->event_data.fork.parent_tgid = task->real_parent->tgid;
ev->event_data.fork.child_pid = task->pid;
ev->event_data.fork.child_tgid = task->tgid;
@@ -79,10 +101,11 @@ void proc_exec_connector(struct task_str
return;

msg = (struct cn_msg*)buffer;
ev = (struct proc_event*)msg->data;
get_seq(&msg->seq, &ev->cpu);
+ get_timestamp(&ev->timestamp);
ev->what = PROC_EVENT_EXEC;
ev->event_data.exec.process_pid = task->pid;
ev->event_data.exec.process_tgid = task->tgid;

memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
@@ -112,10 +135,11 @@ void proc_id_connector(struct task_struc
ev->event_data.id.r.rgid = task->gid;
ev->event_data.id.e.egid = task->egid;
} else
return;
get_seq(&msg->seq, &ev->cpu);
+ get_timestamp(&ev->timestamp);

memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
msg->ack = 0; /* not used */
msg->len = sizeof(*ev);
cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
@@ -131,10 +155,11 @@ void proc_exit_connector(struct task_str
return;

msg = (struct cn_msg*)buffer;
ev = (struct proc_event*)msg->data;
get_seq(&msg->seq, &ev->cpu);
+ get_timestamp(&ev->timestamp);
ev->what = PROC_EVENT_EXIT;
ev->event_data.exit.process_pid = task->pid;
ev->event_data.exit.process_tgid = task->tgid;
ev->event_data.exit.exit_code = task->exit_code;
ev->event_data.exit.exit_signal = task->exit_signal;
@@ -163,10 +188,11 @@ static void cn_proc_ack(int err, int rcv
return;

msg = (struct cn_msg*)buffer;
ev = (struct proc_event*)msg->data;
msg->seq = rcvd_seq;
+ get_timestamp(&ev->timestamp);
ev->cpu = -1;
ev->what = PROC_EVENT_NONE;
ev->event_data.ack.err = err;
memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
msg->ack = rcvd_ack + 1;
Index: linux-2.6.15-rc5/include/linux/cn_proc.h
===================================================================
--- linux-2.6.15-rc5.orig/include/linux/cn_proc.h
+++ linux-2.6.15-rc5/include/linux/cn_proc.h
@@ -24,10 +24,11 @@

#ifndef CN_PROC_H
#define CN_PROC_H

#include <linux/types.h>
+#include <linux/time.h>
#include <linux/connector.h>

/*
* Userspace sends this enum to register with the kernel that it is listening
* for events on the connector.
@@ -63,10 +64,11 @@ struct proc_event {
/* "next" should be 0x00000400 */
/* "last" is the last process event: exit */
PROC_EVENT_EXIT = 0x80000000
} what;
__u32 cpu;
+ struct timespec timestamp;
union { /* must be last field of proc_event struct */
struct {
__u32 err;
} ack;


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-12-06 03:32    [W:0.041 / U:1.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site