From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>,
ruifeng.zhang1@unisoc.com,
Steven Sistare <steven.sistare@oracle.com>,
Prarit Bhargava <prarit@redhat.com>, Baoquan He <bhe@redhat.com>,
zhang.lyra@gmail.com, cixi.geng1@unisoc.com,
Orson Zhai <orsonzhai@gmail.com>, Dave Young <dyoung@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
John Ogness <john.ogness@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Jon DeVree <nuxi@vault24.org>,
Thomas Gleixner <tglx@linutronix.de>,
Salvatore Bonaccorso <carnil@debian.org>,
Stephen Boyd <sboyd@kernel.org>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Orson Zhai <orson.zhai@unisoc.com>,
John Stultz <john.stultz@linaro.org>
Subject: Re: [RFC PATCH] printk: Change timestamp to triplet as mono, boot and real
Date: Thu, 13 Aug 2020 20:31:55 +0900 [thread overview]
Message-ID: <20200813113155.GA483@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20200813102258.GL12903@alley>
On (20/08/13 12:22), Petr Mladek wrote:
>
> + would take more space (prefix + text vs. binary representation)
Dict buffer is allocated regardless of how we use it, and only printks
from drivers/* (dev_printk*) add dict payload. It might be the case
that on some (if not most) systems dict pages are not used 90% of times
(if not 99%).
> + not reliable because dict is currently dropped when no space
Well, in the perfect world this is a problem, but "maybe not having
alternative timestamps sometimes" can be OK approach for people who
wants to use those triplet timestamps.
But, in general, how real this problem is? What I sae so far (on my boxes)
was that printk messages are longer than dict payload.
Example:
6,223,93298,-,caller=T1;acpi PNP0A08:00: _OSC: OS supports [Segments MSI HPX-Type3]
SUBSYSTEM=acpi
DEVICE=+acpi:PNP0A08:00
6,224,93413,-,caller=T1;acpi PNP0A08:00: _OSC: not requesting OS control; OS requires [ExtendedConfig ASPM ClockPM MSI]
SUBSYSTEM=acpi
DEVICE=+acpi:PNP0A08:00
6,225,93540,-,caller=T1;PCI host bridge to bus 0000:00
6,226,93541,-,caller=T1;pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]
SUBSYSTEM=pci_bus
DEVICE=+pci_bus:0000:00
It might be the case, that overflowing dict buffer, without first overflowing
printk buffer, can be rather challenging.
> + it would make the controversial dictionary feature more important
Yes. But, for the time being, this controversial dict feature allocates
pages for dict buffer anyway.
-ss
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Orson Zhai <orsonzhai@gmail.com>,
Prarit Bhargava <prarit@redhat.com>,
Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
John Stultz <john.stultz@linaro.org>,
Stephen Boyd <sboyd@kernel.org>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
zhang.lyra@gmail.com, ruifeng.zhang1@unisoc.com,
cixi.geng1@unisoc.com, Orson Zhai <orson.zhai@unisoc.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Steven Sistare <steven.sistare@oracle.com>,
Dominique Martinet <asmadeus@codewreck.org>,
Jon DeVree <nuxi@vault24.org>,
Salvatore Bonaccorso <carnil@debian.org>,
John Ogness <john.ogness@linutronix.de>
Subject: Re: [RFC PATCH] printk: Change timestamp to triplet as mono, boot and real
Date: Thu, 13 Aug 2020 20:31:55 +0900 [thread overview]
Message-ID: <20200813113155.GA483@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20200813102258.GL12903@alley>
On (20/08/13 12:22), Petr Mladek wrote:
>
> + would take more space (prefix + text vs. binary representation)
Dict buffer is allocated regardless of how we use it, and only printks
from drivers/* (dev_printk*) add dict payload. It might be the case
that on some (if not most) systems dict pages are not used 90% of times
(if not 99%).
> + not reliable because dict is currently dropped when no space
Well, in the perfect world this is a problem, but "maybe not having
alternative timestamps sometimes" can be OK approach for people who
wants to use those triplet timestamps.
But, in general, how real this problem is? What I sae so far (on my boxes)
was that printk messages are longer than dict payload.
Example:
6,223,93298,-,caller=T1;acpi PNP0A08:00: _OSC: OS supports [Segments MSI HPX-Type3]
SUBSYSTEM=acpi
DEVICE=+acpi:PNP0A08:00
6,224,93413,-,caller=T1;acpi PNP0A08:00: _OSC: not requesting OS control; OS requires [ExtendedConfig ASPM ClockPM MSI]
SUBSYSTEM=acpi
DEVICE=+acpi:PNP0A08:00
6,225,93540,-,caller=T1;PCI host bridge to bus 0000:00
6,226,93541,-,caller=T1;pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]
SUBSYSTEM=pci_bus
DEVICE=+pci_bus:0000:00
It might be the case, that overflowing dict buffer, without first overflowing
printk buffer, can be rather challenging.
> + it would make the controversial dictionary feature more important
Yes. But, for the time being, this controversial dict feature allocates
pages for dict buffer anyway.
-ss
next prev parent reply other threads:[~2020-08-13 11:32 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-11 4:40 [RFC PATCH] printk: Change timestamp to triplet as mono, boot and real Orson Zhai
2020-08-11 4:40 ` Orson Zhai
2020-08-11 4:56 ` Randy Dunlap
2020-08-11 4:56 ` Randy Dunlap
2020-08-11 9:44 ` Petr Mladek
2020-08-11 9:44 ` Petr Mladek
2020-08-11 12:05 ` Thomas Gleixner
2020-08-11 12:05 ` Thomas Gleixner
2020-08-11 13:02 ` Petr Mladek
2020-08-11 13:02 ` Petr Mladek
2020-08-11 13:43 ` Prarit Bhargava
2020-08-11 13:43 ` Prarit Bhargava
2020-08-13 1:55 ` Sergey Senozhatsky
2020-08-13 1:55 ` Sergey Senozhatsky
2020-08-13 10:22 ` Petr Mladek
2020-08-13 10:22 ` Petr Mladek
2020-08-13 11:31 ` Sergey Senozhatsky [this message]
2020-08-13 11:31 ` Sergey Senozhatsky
2020-08-14 9:50 ` Petr Mladek
2020-08-14 9:50 ` Petr Mladek
2020-08-13 10:26 ` Thomas Gleixner
2020-08-13 10:26 ` Thomas Gleixner
2020-08-14 6:34 ` Dave Young
2020-08-14 6:34 ` Dave Young
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200813113155.GA483@jagdpanzerIV.localdomain \
--to=sergey.senozhatsky@gmail.com \
--cc=asmadeus@codewreck.org \
--cc=bhe@redhat.com \
--cc=carnil@debian.org \
--cc=cixi.geng1@unisoc.com \
--cc=dyoung@redhat.com \
--cc=john.ogness@linutronix.de \
--cc=john.stultz@linaro.org \
--cc=kexec@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nuxi@vault24.org \
--cc=orson.zhai@unisoc.com \
--cc=orsonzhai@gmail.com \
--cc=pasha.tatashin@soleen.com \
--cc=pmladek@suse.com \
--cc=prarit@redhat.com \
--cc=rostedt@goodmis.org \
--cc=ruifeng.zhang1@unisoc.com \
--cc=sboyd@kernel.org \
--cc=steven.sistare@oracle.com \
--cc=tglx@linutronix.de \
--cc=vgoyal@redhat.com \
--cc=zhang.lyra@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.