From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Prarit Bhargava <prarit@redhat.com>,
Mark Salyzyn <salyzyn@android.com>,
Chunyan Zhang <zhang.lyra@gmail.com>,
Orson Zhai <orsonzhai@gmail.com>,
Changki Kim <changki.kim@samsung.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] printk: Store all three timestamps
Date: Thu, 24 Sep 2020 12:37:26 +0200 [thread overview]
Message-ID: <20200924103726.GM6442@alley> (raw)
In-Reply-To: <878sd0m4c3.fsf@jogness.linutronix.de>
On Thu 2020-09-24 02:06:12, John Ogness wrote:
> On 2020-09-23, Petr Mladek <pmladek@suse.com> wrote:
> > diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h
> > index 0adaa685d1ca..09082c8472d3 100644
> > --- a/kernel/printk/printk_ringbuffer.h
> > +++ b/kernel/printk/printk_ringbuffer.h
> > @@ -14,7 +15,7 @@
> > */
> > struct printk_info {
> > u64 seq; /* sequence number */
> > - u64 ts_nsec; /* timestamp in nanoseconds */
> > + struct ktime_timestamps ts; /* timestamps */
>
> Until now struct printk_info has contained generic types. If we add
> struct ktime_timestamps, we may start storing more than we need. For
> example, if more (possibly internal) fields are added to struct
> ktime_timestamps that printk doesn't care about. We may prefer to
> generically and explicitly store the information we care about:
>
> u64 ts_mono;
> u64 ts_boot;
> u64 ts_real;
>
> Or create our own struct printk_ts to copy the fields of interest to.
I would like to have a structure if we have more timestamps.
Honestly, printk-specific structure sounds like an overhead to me.
How big is the chance that struct ktime_timestamps ts would get
modified? It has been created for printk after all.
That said, I could live with printk-specific structure.
We might even need it if we need to store also local_clock().
Best Regards,
Petr
next prev parent reply other threads:[~2020-09-24 10:37 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 13:56 [RFC 0/2] printk: Add more metadata for each record Petr Mladek
2020-09-23 13:56 ` [PATCH 1/2] printk: Store all three timestamps Petr Mladek
2020-09-23 22:12 ` John Ogness
2020-09-24 1:45 ` Sergey Senozhatsky
2020-09-24 11:49 ` Petr Mladek
[not found] ` <CAJ-C09hqwOJhSXx1h40q96xhNZFXxP6dUVfjUQZpO4ZhOMZLbQ@mail.gmail.com>
2020-09-25 9:51 ` Petr Mladek
2020-09-24 0:00 ` John Ogness
2020-09-24 10:37 ` Petr Mladek [this message]
2020-09-23 13:56 ` [RFC 2/2] printk: Add more information about the printk caller Petr Mladek
2020-09-24 1:40 ` Sergey Senozhatsky
2020-09-24 11:58 ` Petr Mladek
2020-09-24 2:17 ` Sergey Senozhatsky
2020-09-24 8:23 ` John Ogness
2020-09-24 13:26 ` Petr Mladek
2020-09-24 13:06 ` Petr Mladek
2020-09-24 4:24 ` Ahmed S. Darwish
2020-09-24 12:53 ` Petr Mladek
2020-09-24 13:38 ` Petr Mladek
2020-09-25 0:54 ` Sergey Senozhatsky
2020-09-25 10:20 ` Petr Mladek
2020-10-21 11:48 ` 김창기
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