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Date: Sat, 8 Oct 2016 04:33:03 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Jan Kara <jack@suse.cz>, Andrew Morton <akpm@linux-foundation.org>,
        Tejun Heo <tj@kernel.org>, Calvin Owens <calvinowens@fb.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Mel Gorman <mgorman@techsingularity.net>,
        Steven Rostedt <rostedt@goodmis.org>, linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC][PATCHv2 3/7] printk: introduce per-cpu alt_print seq buffer
Message-ID: <20161007193303.GA3496@swordfish>
References: <20160930151758.8965-1-sergey.senozhatsky@gmail.com>
 <20160930151758.8965-4-sergey.senozhatsky@gmail.com>
 <20161006130849.GG13369@pathway.suse.cz>
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On (10/06/16 15:08), Petr Mladek wrote:
[..]
> > +static int vprintk_nmi(const char *fmt, va_list args)
> > +{
> > +	struct alt_printk_seq_buf *s = this_cpu_ptr(&nmi_print_seq);
> > +	int add;
> > +
> > +	add = alt_printk_log_store(s, fmt, args);
> > +	if (!add)
> > +		atomic_inc(&nmi_message_lost);
> 
> This would could also empty string as an error. A solution might be
> update alt_printk_log_store() to return -1 in case of lost log.
> Note that vprintk_nmi() still needs to return 0 in this case to
> stay compatible with printk().

will do.

> > +static int vprintk_alt(const char *fmt, va_list args)
> > +{
> > +	struct alt_printk_seq_buf *s = this_cpu_ptr(&alt_print_seq);
> > +
> > +	return alt_printk_log_store(s, fmt, args);
> 
> We should handle lost strings here as well. But it can be
> done in a followup patch.

ok, will do.

	-ss