Messages in this thread | | | Date | Wed, 26 Jan 2022 18:34:36 -0800 | From | Jakub Kicinski <> | Subject | Re: [PATCH v3 net-next 2/2] net: mscc: ocelot: use bulk reads for stats |
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On Mon, 24 Jan 2022 23:15:31 -0800 Colin Foster wrote: > Create and utilize bulk regmap reads instead of single access for gathering > stats. The background reading of statistics happens frequently, and over > a few contiguous memory regions. > > High speed PCIe buses and MMIO access will probably see negligible > performance increase. Lower speed buses like SPI and I2C could see > significant performance increase, since the bus configuration and register > access times account for a large percentage of data transfer time. > > Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
> +static int ocelot_prepare_stats_regions(struct ocelot *ocelot) > +{ > + struct ocelot_stats_region *region = NULL; > + unsigned int last; > + int i; > + > + INIT_LIST_HEAD(&ocelot->stats_regions); > + > + for (i = 0; i < ocelot->num_stats; i++) { > + if (region && ocelot->stats_layout[i].offset == last + 1) { > + region->count++; > + } else { > + region = devm_kzalloc(ocelot->dev, sizeof(*region), > + GFP_KERNEL); > + if (!region) > + return -ENOMEM; > + > + region->offset = ocelot->stats_layout[i].offset; > + region->count = 1; > + list_add_tail(®ion->node, &ocelot->stats_regions); > + } > + > + last = ocelot->stats_layout[i].offset; > + } > + > + list_for_each_entry(region, &ocelot->stats_regions, node) { > + region->buf = devm_kzalloc(ocelot->dev, > + region->count * sizeof(*region->buf), > + GFP_KERNEL);
devm_kcalloc()
> +
unnecessary new line
> + if (!region->buf) > + return -ENOMEM;
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