Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <7702bdc2-78ce-00f5-d5a4-c06527c3ae72@igalia.com>
Date:   Tue, 22 Feb 2022 11:08:22 -0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.6.1
Subject: Re: [PATCH V6] panic: Move panic_print before kmsg dumpers
Content-Language: en-US
To:     Sergey Senozhatsky <senozhatsky@chromium.org>, bhe@redhat.com,
        pmladek@suse.com
Cc:     linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        anton@enomsg.org, ccross@android.com, dyoung@redhat.com,
        feng.tang@intel.com, john.ogness@linutronix.de,
        keescook@chromium.org, kernel@gpiccoli.net,
        kexec@lists.infradead.org, rostedt@goodmis.org,
        tony.luck@intel.com, vgoyal@redhat.com
References: <20220214141308.841525-1-gpiccoli@igalia.com>
 <YhRAOQbH15E7y9s8@google.com>
From:   "Guilherme G. Piccoli" <gpiccoli@igalia.com>
In-Reply-To: <YhRAOQbH15E7y9s8@google.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 21/02/2022 22:45, Sergey Senozhatsky wrote:
> [...]
> Yeah, if Petr is fine with that then I'm OK. But at the same time,
> we have `panic_print' which is a bit mask of what panic_print_sys_info()
> should do. And now we also have a boolean `console_flush` flag that tells
> panic_print_sys_info() to ignore some (one as of now) bits of `panic_print'.
> 
> So _maybe_ panic_print_sys_info() can just accept panic_print as
> its parameter and then we can do something like this (as an example)
> 
> 	panic_print_sys_info(panic_print & ~PANIC_PRINT_ALL_PRINTK_MSG);
> 
> 
>>  	if (panic_print & PANIC_PRINT_ALL_CPU_BT)
>>  		trigger_all_cpu_backtrace();
>> @@ -286,6 +289,8 @@ void panic(const char *fmt, ...)
>>  	 */
>>  	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
> 
> [..]
> 
>> +	panic_print_sys_info(false);
> 
> Merely because `panic_print_sys_info(false);` doesn't tell much to a reader.
> Like what is print sys info false?
> 
> Or did you already discuss this?

Hi Sergey, thanks for your feedback. So, personally I prefer having the
flag - for me it's clear, it's just a matter of reading the prototype -
either we print the info _or_ we console_flush.

But let's see if others have a preference - if the preference is to use
the bitmask as you suggest, we can do it in a next version.

Cheers,


Guilherme