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Date:   Mon, 1 Feb 2021 14:17:17 +0100
From:   Petr Mladek <pmladek@suse.com>
To:     John Ogness <john.ogness@linutronix.de>
Cc:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH printk-rework 08/12] printk: introduce a kmsg_dump
 iterator
Message-ID: <YBf/XUmgflhMHtBx@alley>
References: <20210126211551.26536-1-john.ogness@linutronix.de>
 <20210126211551.26536-9-john.ogness@linutronix.de>
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In-Reply-To: <20210126211551.26536-9-john.ogness@linutronix.de>
Precedence: bulk

On Tue 2021-01-26 22:21:47, John Ogness wrote:
> Rather than store the iterator information into the registered
> kmsg_dump structure, create a separate iterator structure. The
> kmsg_dump_iter structure can reside on the stack of the caller,
> thus allowing lockless use of the kmsg_dump functions.
> 
> This is in preparation for removal of @logbuf_lock.

> diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
> index 76cc4122d08e..ecc98f549d93 100644
> --- a/include/linux/kmsg_dump.h
> +++ b/include/linux/kmsg_dump.h
> @@ -29,6 +29,18 @@ enum kmsg_dump_reason {
>  	KMSG_DUMP_MAX
>  };
>  
> +/**
> + * struct kmsg_dumper_iter - iterator for kernel crash message dumper
> + * @active:	Flag that specifies if this is currently dumping
> + * @cur_seq:	The record to dump (private)
> + * @next_seq:	The first record of the next block (private)

Just to be sure. This description should get update if you agree with
the alternative one in the 1st patch.

> + */
> +struct kmsg_dumper_iter {
> +	bool	active;
> +	u64	cur_seq;
> +	u64	next_seq;
> +};
> +

Otherwise, I like this change.

Best Regards,
Petr