Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 7 Nov 2019 13:46:15 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     Jan Stancek <jstancek@redhat.com>, linux-kernel@vger.kernel.org,
        ltp@lists.linux.it, viro@zeniv.linux.org.uk,
        kstewart@linuxfoundation.org, gregkh@linuxfoundation.org,
        rfontana@redhat.com
Subject: Re: [PATCH] kernel: use ktime_get_real_ts64() to calculate
 acct.ac_btime
Message-ID: <20191107124615.GG4131@hirez.programming.kicks-ass.net>
References: <a87876829697e1b3c63601b1401a07af79eddae6.1572651216.git.jstancek@redhat.com>
 <20191107123224.GA6315@hirez.programming.kicks-ass.net>
 <alpine.DEB.2.21.1911071335320.4256@nanos.tec.linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <alpine.DEB.2.21.1911071335320.4256@nanos.tec.linutronix.de>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Nov 07, 2019 at 01:40:47PM +0100, Thomas Gleixner wrote:
> Typing real_start_time makes me really cringe.

I have a patch fixing that...

---
Subject: kernel: Rename tsk->real_start_time
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu Nov  7 11:07:58 CET 2019

Since it stores CLOCK_BOOTTIME, not, as the name suggests,
CLOCK_REALTIME, let's rename real_start_time.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1132,7 +1132,7 @@ static int de_thread(struct task_struct
 		 * also take its birthdate (always earlier than our own).
 		 */
 		tsk->start_time = leader->start_time;
-		tsk->real_start_time = leader->real_start_time;
+		tsk->start_boottime = leader->start_boottime;
 
 		BUG_ON(!same_thread_group(leader, tsk));
 		BUG_ON(has_group_leader_pid(tsk));
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -533,7 +533,7 @@ static int do_task_stat(struct seq_file
 	nice = task_nice(task);
 
 	/* convert nsec -> ticks */
-	start_time = nsec_to_clock_t(task->real_start_time);
+	start_time = nsec_to_clock_t(task->start_boottime);
 
 	seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
 	seq_puts(m, " (");
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -879,7 +879,7 @@ struct task_struct {
 	u64				start_time;
 
 	/* Boot based time in nsecs: */
-	u64				real_start_time;
+	u64				start_boottime;
 
 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
 	unsigned long			min_flt;
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2130,7 +2130,7 @@ static __latent_entropy struct task_stru
 	 */
 
 	p->start_time = ktime_get_ns();
-	p->real_start_time = ktime_get_boottime_ns();
+	p->start_boottime = ktime_get_boottime_ns();
 
 	/*
 	 * Make it visible to the rest of the system, but dont wake it up yet.