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Mon, 8 Jun 2020 04:07:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591603677; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZbN71+DLOQDLMNnWvQpaN1N2Hub7a1AniDuqT74J44I=; b=JRmAh+ycXt69Cfk7HyNItOR+waL1agt4DbX141wIvqhgFBgPW5r+7SsJlqqA8DVF87pxzo mZkULe6iH+GTKui1TPJfM1Vx6sqF4NY41zGwWPt3++7gWxiUQVgRN59wA/EJddRwW2LtAY 7f2cLtDcHxf8+jLa2v9runTSQpPbzzc= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-176-Pmfw7qhiOKCLnAqIgPfowA-1; Mon, 08 Jun 2020 04:07:56 -0400 X-MC-Unique: Pmfw7qhiOKCLnAqIgPfowA-1 Received: by mail-qk1-f199.google.com with SMTP id p7so13630282qkf.21 for ; Mon, 08 Jun 2020 01:07:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZbN71+DLOQDLMNnWvQpaN1N2Hub7a1AniDuqT74J44I=; b=tZUNDOwmObWQ7aPsQGIHuMZqOY87HW34SNTNOBcV24zsS6AXZlN8BmSz86bUY6baIB X2Wj2oI+cAvnBmHBgfKfLI+rOnoZCbN6aK7rXk4k0KW/48HPeCuspfidbTI8M9CiAtIc QWUUbdIJJFa8+ceeQTW1hQ9rgurbzk1XV4ZdMWSLqPTIfq3U9+pNkz+2Ky8eBbYGP1xE LCiNd0pEYWMPvYBj9T9D7a2/2thYjqr8ARHPUt6MbuA/YNnACDGAEepdxPD96GZUsweU 0O80yej7gbw/S1/66qYYh55kb085j9g31ZbXwlOqHd8R1pz2/7B64mxCeVGAp8ggIei2 XDCw== X-Gm-Message-State: AOAM532OgUzW3RPCtZZIqZyiFd2jsIQndtPIgkmII5eOf486g4A962FP dBRRtQBvGYswp8jMXNaW5kpGB23AkDN4dUyjO+1pVrk3t77pEMy7J9ynf28n5EdHdqHiei4ZpHK W35jAbnDxKMYJf2Sbo8WH2YWe7EI/BOhUZdne+DSi X-Received: by 2002:ad4:4d8f:: with SMTP id cv15mr21509534qvb.195.1591603675835; Mon, 08 Jun 2020 01:07:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzWj54BrhXlaXyGur0GgPLTutUYY8qIY0pbnzZPMB2tmAwlSKjBWtONJhERHg/zCg3vBVkCjREgic7BjZKcplA= X-Received: by 2002:ad4:4d8f:: with SMTP id cv15mr21509514qvb.195.1591603675583; Mon, 08 Jun 2020 01:07:55 -0700 (PDT) MIME-Version: 1.0 References: <20200605194642.62278-1-pasha.tatashin@soleen.com> In-Reply-To: <20200605194642.62278-1-pasha.tatashin@soleen.com> From: Bhupesh Sharma Date: Mon, 8 Jun 2020 13:37:42 +0530 Message-ID: Subject: Re: [PATCH] kexec: dump kmessage before machine_kexec To: Pavel Tatashin Cc: James Morris , sashal@kernel.org, pmladek@suse.com, Eric Biederman , Kees Cook , anton@enomsg.org, ccross@android.com, "Luck, Tony" , kexec mailing list , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pavel, On Sat, Jun 6, 2020 at 1:16 AM 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 > --- > kernel/kexec_core.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c > index c19c0dad1ebe..50027f759a97 100644 > --- a/kernel/kexec_core.c > +++ b/kernel/kexec_core.c > @@ -37,6 +37,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -1181,6 +1182,7 @@ int kernel_kexec(void) > machine_shutdown(); > } > > + kmsg_dump(KMSG_DUMP_SHUTDOWN); > machine_kexec(kexec_image); > > #ifdef CONFIG_KEXEC_JUMP > -- > 2.25.1 LGTM, so: Reviewed-by: Bhupesh Sharma Thanks.