From: Kees Cook <keescook@chromium.org>
To: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: James Morris <jmorris@namei.org>, Sasha Levin <sashal@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
anton@enomsg.org, ccross@android.com,
Tony Luck <tony.luck@intel.com>,
robh+dt@kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v1 0/3] allow ramoops to collect all kmesg_dump events
Date: Mon, 4 May 2020 12:30:47 -0700 [thread overview]
Message-ID: <202005041230.806B1581D@keescook> (raw)
In-Reply-To: <CA+CK2bAJgKR+=Tby91gU-ZKy29Juv_oJinCTFAWRaKiiro2vkg@mail.gmail.com>
On Mon, May 04, 2020 at 03:17:40PM -0400, Pavel Tatashin wrote:
> On Mon, May 4, 2020 at 3:12 PM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Mon, May 04, 2020 at 02:47:45PM -0400, Pavel Tatashin wrote:
> > > > > # reboot -f
> > > > >
> > > > > After VM is back:
> > > > >
> > > > > # mount -t pstore pstore /mnt
> > > > > # head /mnt/dmesg-ramoops-0
> > > > > Restart#1 Part1
> > > >
> > > > Is there a reason that using ramoops.console_size isn't sufficient for
> > > > this?
> > >
> > > Unfortunately, the console option is not working for us (Microsoft),
> > > we have an embedded device with a serial console, and the baud rate
> > > reduces the reboot performance, so we must keep the console quiet. We
> > > also want to be able collect full shutdown logs from the field that
> > > are collected during kexec based updates.
> >
> > I meant collecting console via pstore (i.e. /mnt/console-ramoops-0). Are
> > you saying that's still too large for your situation?
>
> pstore /mnt/console-ramoops-0 outputs only messages below the console
> loglevel, and our console loglevel is set to 3 due to slowness of
> serial console. Which means only errors and worse types of messages
> are recorded. AFAIK, there is no way to have different log levels for
> different consoles.
Ah-ha! Okay, thanks. Please include this rationale in the v2 changelog.
That makes perfect sense; I just didn't see it and maybe others will
need the same clarity too. Thanks!
-Kees
--
Kees Cook
next prev parent reply other threads:[~2020-05-04 19:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-02 14:35 [PATCH v1 0/3] allow ramoops to collect all kmesg_dump events Pavel Tatashin
2020-05-02 14:35 ` [PATCH v1 1/3] printk: honor the max_reason field in kmsg_dumper Pavel Tatashin
2020-05-04 17:15 ` Steven Rostedt
2020-05-04 17:56 ` Pavel Tatashin
2020-05-04 18:12 ` Kees Cook
2020-05-04 18:40 ` Pavel Tatashin
2020-05-05 1:02 ` Sergey Senozhatsky
2020-05-05 2:52 ` Pavel Tatashin
2020-05-05 3:12 ` Pavel Tatashin
2020-05-05 4:21 ` Pavel Tatashin
2020-05-05 10:50 ` Sergey Senozhatsky
2020-05-02 14:35 ` [PATCH v1 2/3] pstore/ram: allow to dump kmesg during regular reboot Pavel Tatashin
2020-05-04 19:29 ` Kees Cook
2020-05-04 20:30 ` Pavel Tatashin
2020-05-04 20:54 ` Kees Cook
2020-05-02 14:35 ` [PATCH v1 3/3] ramoops: add dump_all optional field to ramoops DT node Pavel Tatashin
2020-05-04 19:29 ` Kees Cook
2020-05-04 20:00 ` Pavel Tatashin
2020-05-05 15:14 ` Pavel Tatashin
2020-05-04 18:14 ` [PATCH v1 0/3] allow ramoops to collect all kmesg_dump events Kees Cook
2020-05-04 18:47 ` Pavel Tatashin
2020-05-04 19:12 ` Kees Cook
2020-05-04 19:17 ` Pavel Tatashin
2020-05-04 19:30 ` Kees Cook [this message]
2020-05-04 20:00 ` Pavel Tatashin
2020-05-05 12:36 ` Sergey Senozhatsky
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