From: Steven Rostedt <rostedt@goodmis.org>
To: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: daniel.wagner@bmw-carit.de, masami.hiramatsu.pt@hitachi.com,
namhyung@kernel.org, josh@joshtriplett.org, andi@firstfloor.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 06/10] trace: Add lock-free tracing_map
Date: Fri, 12 Jun 2015 14:17:31 -0400 [thread overview]
Message-ID: <20150612141731.01232907@gandalf.local.home> (raw)
In-Reply-To: <e025909c160df379949ea3fb80c76d43a8116587.1433797842.git.tom.zanussi@linux.intel.com>
On Mon, 8 Jun 2015 16:32:05 -0500
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
> Add tracing_map, a special-purpose lock-free map for tracing.
>
> tracing_map is designed to aggregate or 'sum' one or more values
> associated with a specific object of type tracing_map_elt, which
What is "elt"? I don't see it explained anywhere.
> is associated by the map to a given key.
>
> It provides various hooks allowing per-tracer customization and is
> separated out into a separate file in order to allow it to be shared
> between multiple tracers, but isn't meant to be generally used outside
> of that context.
>
> The tracing_map implementation was inspired by lock-free map
> algorithms originated by Dr. Cliff Click:
>
> http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable
> http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf
>
> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
> +/**
> + * tracing_map_update_sum - Add a value to a tracing_map_elt's sum
> + * @elt: The tracing_map_elt
Not a very useful comment, as I have no idea what "elt" is.
I'll continue to review this patch about the mysterious element "elt".
-- Steve
> + * @i: The index of the given sum associated with the tracing_map_elt
> + * @n: The value to add to the sum
> + *
> + * Add n to sum i associated with the specified tracing_map_elt
> + * instance. The index i is the index returned by the call to
> + * tracing_map_add_sum_field() when the tracing map was set up.
> + */
> +void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n)
> +{
> + atomic64_add(n, &elt->fields[i].sum);
> +}
> +
next prev parent reply other threads:[~2015-06-12 18:17 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-08 21:31 [PATCH v7 00/10] tracing: 'hist' triggers Tom Zanussi
2015-06-08 21:32 ` [PATCH v3 01/10] tracing: Update cond flag when enabling or disabling a trigger Tom Zanussi
2015-06-12 18:01 ` Steven Rostedt
2015-06-13 8:45 ` Daniel Wagner
2015-06-15 7:02 ` Daniel Wagner
2015-06-29 20:25 ` Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 02/10] tracing: Make ftrace_event_field checking functions available Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 03/10] tracing: Add event record param to trigger_ops.func() Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 04/10] tracing: Add get_syscall_name() Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 05/10] tracing: Add a per-event-trigger 'paused' field Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 06/10] trace: Add lock-free tracing_map Tom Zanussi
2015-06-12 18:17 ` Steven Rostedt [this message]
2015-06-29 20:19 ` Tom Zanussi
2015-06-12 20:47 ` Steven Rostedt
2015-06-12 20:52 ` Steven Rostedt
2015-06-29 20:33 ` Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 07/10] tracing: Add 'hist' event trigger command Tom Zanussi
2015-06-10 14:14 ` Masami Hiramatsu
2015-06-10 16:32 ` Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 08/10] tracing: Add enable_hist/disable_hist triggers Tom Zanussi
2015-06-08 21:32 ` [PATCH v7 09/10] tracing: Add 'hist' trigger Documentation Tom Zanussi
2015-06-08 21:32 ` [PATCH v3 10/10] ftrace: Add function_hist tracer Tom Zanussi
2015-06-10 2:57 ` [PATCH v7 00/10] tracing: 'hist' triggers Masami Hiramatsu
2015-06-11 3:05 ` Namhyung Kim
2015-06-11 20:42 ` Tom Zanussi
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