32eb645332
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@wanadoo.fr>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.