General Tips

Your code must not only "work", but also meet certain standards. Below are some tips for assignments, along with related penalties for non-compliance:

• 0.2: compilation warnings
• 0.1: 10-20 lines longer than 80 characters;
• 0.2: more than 20 lines longer than 80 characters;
• 0.1: duplicated code;
• 0.1: magic numbers, not symbolic constants;
• 0.1: identation where tabs are mixed with spaces;
• 0.1: mixed line endings;
• 0.1: trailing whitespace; do not leave spaces or tabs at the end of lines;
• 0.1: long functions(> 150 de lines);
• 0.2: very long functions (> 300 de lines);
• 0.1: commented code; for debugging we recommend using a macro;
• 0.1: inappropriate comments; we recommend briefly browsing the Documentation/kernel-doc-nano-HOWTO.txt file for infomation about comment format;
• 0.1: functions and variables used only locally that are not static;
• 0.2: no copy_ {to, from} _user functions are used where needed;
• 0.2: the return values of the functions are not checked;
• 0.1: no relevant error codes are returned;
• 0.2/-0.3: synchronization problems (-0.2 partial synchronizations, -0.3 synchronization mechanisms are missing or incorrect);
• 0.1: inclusion of binary or irrelevant files in the archive;
• 0.2: memory leaks;
• 0.3: use of blocking operations in atomic context;

You can check most style comments using scripts/checkpatch.pl, found in any Linux tree. For specific situations where you break the rules, argue with a comment or specification in the README file.

Usage

$ scripts/checkpatch.pl --no-tree --terse -f my-homework.c

For more information on coding style, you can read the file Coding Style.