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Date: Tue, 6 Dec 2011 10:30:25 -0500
From: Christoph Hellwig <hch@infradead.org>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
        Jens Axboe <axboe@kernel.dk>, Steven Rostedt <rostedt@goodmis.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Rik van Riel <riel@redhat.com>,
        Linux Memory Management List <linux-mm@kvack.org>,
        linux-fsdevel@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 7/9] readahead: add vfs/readahead tracing event
Message-ID: <20111206153025.GA18974@infradead.org>
References: <20111129130900.628549879@intel.com>
 <20111129131456.797240894@intel.com>
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> +	TP_printk("readahead-%s(dev=%d:%d, ino=%lu, "

please don't duplicate the tracepoint name in the output string.
Also don't use braces, as it jsut complicates parsing.

> +		  "req=%lu+%lu, ra=%lu+%d-%d, async=%d) = %d",
> +			ra_pattern_names[__entry->pattern],

Instead of doing a manual array lookup please use __print_symbolic so
that users of the binary interface (like trace-cmd) also get the
right output.

> --- linux-next.orig/mm/readahead.c	2011-11-29 20:58:53.000000000 +0800
> +++ linux-next/mm/readahead.c	2011-11-29 20:59:20.000000000 +0800
> @@ -29,6 +29,9 @@ static const char * const ra_pattern_nam
>  	[RA_PATTERN_ALL]                = "all",
>  };
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/vfs.h>

Maybe we should create a new fs/trace.c just for this instead of stickin
it into the first file that created a tracepoint in the "vfs" namespace.