On Mon, 8 Jun 2015 16:32:05 -0500 Tom Zanussi <tom.zanu...@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.zanu...@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); > +} > + -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
