On 20-11-22, 18:19, Christophe JAILLET wrote: > Use flexible array to simplify memory allocation. > It saves some memory, avoids an indirection when reading the 'clusters' > array and removes some LoC. > > > Detailed explanation: > ==================== > Knowing that: > - each devm_ allocation over-allocates 40 bytes for internal needs > - Some rounding is done by the memory allocator on 8, 16, 32, 64, 96, > 128, 192, 256, 512, 1024, 2048, 4096, 8192 boundaries > > and that: > - sizeof(struct tegra186_cpufreq_data) = 24 > - sizeof(struct tegra186_cpufreq_cluster) = 16 > > Memory allocations in tegra186_cpufreq_probe() are: > data: (24 + 40) = 64 => 64 bytes > data->clusters: (2 * 16 + 40) = 72 => 96 bytes > So a total of 160 bytes are allocated. > 56 for the real need, 80 for internal uses and 24 are wasted. > > > If 'struct tegra186_cpufreq_data' is reordered so that 'clusters' is a > flexible array: > - it saves one pointer in the structure > - only one allocation is needed > > So, only 96 bytes are allocated: > 16 + 2 * 16 + 40 = 88 => 96 bytes > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> > --- Applied. Thanks. -- viresh
