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From: Kees Cook <keescook@chromium.org>
To: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: sashal@kernel.org, pmladek@suse.com, tony.luck@intel.com,
	anton@enomsg.org, kexec@lists.infradead.org, jmorris@namei.org,
	linux-kernel@vger.kernel.org, ebiederm@xmission.com,
	ccross@android.com
Subject: Re: [PATCH] kexec: dump kmessage before machine_kexec
Date: Fri, 5 Jun 2020 14:26:36 -0700	[thread overview]
Message-ID: <202006051426.4F06C696@keescook> (raw)
In-Reply-To: <20200605194642.62278-1-pasha.tatashin@soleen.com>

On Fri, Jun 05, 2020 at 03:46:42PM -0400, 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: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: jmorris@namei.org, sashal@kernel.org, pmladek@suse.com,
	ebiederm@xmission.com, 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: Fri, 5 Jun 2020 14:26:36 -0700	[thread overview]
Message-ID: <202006051426.4F06C696@keescook> (raw)
In-Reply-To: <20200605194642.62278-1-pasha.tatashin@soleen.com>

On Fri, Jun 05, 2020 at 03:46:42PM -0400, 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: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

  reply	other threads:[~2020-06-05 21:26 UTC|newest]

Thread overview: 8+ 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 19:46 ` Pavel Tatashin
2020-06-05 21:26 ` Kees Cook [this message]
2020-06-05 21:26   ` Kees Cook
2020-06-08  8:06 ` Petr Mladek
2020-06-08  8:06   ` Petr Mladek
2020-06-08  8:07 ` Bhupesh Sharma
2020-06-08  8:07   ` Bhupesh Sharma

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