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From: Petr Mladek <pmladek@suse.com>
To: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com,
	keescook@chromium.org, anton@enomsg.org, ccross@android.com,
	tony.luck@intel.com, kexec@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kexec: dump kmessage before machine_kexec
Date: Mon, 8 Jun 2020 10:06:27 +0200	[thread overview]
Message-ID: <20200608080627.GD5099@linux-b0ei> (raw)
In-Reply-To: <20200605194642.62278-1-pasha.tatashin@soleen.com>

On Fri 2020-06-05 15:46:42, Pavel Tatashin wrote:
> kmsg_dump(KMSG_DUMP_SHUTDOWN) is called before
> machine_restart(), machine_halt(), machine_power_off(), the only one that
> is missing is  machine_kexec().
> 
> The dmesg output that it contains can be used to study the shutdown
> performance of both kernel and systemd during kexec reboot.
> 
> Here is example of dmesg data collected after kexec:
> 
> root@dplat-cp22:~# cat /sys/fs/pstore/dmesg-ramoops-0 | tail
> ...
> <6>[   70.914592] psci: CPU3 killed (polled 0 ms)
> <5>[   70.915705] CPU4: shutdown
> <6>[   70.916643] psci: CPU4 killed (polled 4 ms)
> <5>[   70.917715] CPU5: shutdown
> <6>[   70.918725] psci: CPU5 killed (polled 0 ms)
> <5>[   70.919704] CPU6: shutdown
> <6>[   70.920726] psci: CPU6 killed (polled 4 ms)
> <5>[   70.921642] CPU7: shutdown
> <6>[   70.922650] psci: CPU7 killed (polled 0 ms)
> 
> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>

Reviewed-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr

  parent reply	other threads:[~2020-06-08  8:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-05 19:46 [PATCH] kexec: dump kmessage before machine_kexec Pavel Tatashin
2020-06-05 21:26 ` Kees Cook
2020-06-08  8:06 ` Petr Mladek [this message]
2020-06-08  8:07 ` Bhupesh Sharma

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