Documentation/development-process/4.Coding

10 number of ways in which kernel developers can go wrong.  Then the focus
11 will shift toward doing things right and the tools which can help in that
37 win before the code can be merged.  Putting code into the kernel means
52 can never be transgressed.  If there is a good reason to go against the
63 But experience has shown that excessive or premature abstraction can be
103 Conditionally-compiled code can be confined to functions which, if the code
118 Inline functions present a hazard of their own, though.  Programmers can
121 however, can actually reduce performance.  Since their code is replicated
123 That, in turn, creates pressure on the processor's memory caches, which can
174 One final hazard worth mentioning is this: it can be tempting to make a
182 It is often argued that a regression can be justified if it causes things
208 of us can reach.  What we can hope to do, though, is to catch and fix as
211 array of tools which can catch a wide variety of obscure problems in an
217 Contemporary versions of gcc can detect (and warn about) a large number of
235    generated by these warnings can be verbose, but one need not worry about
244  - DEBUG_SLAB can find a variety of memory allocation and use errors; it
258 each other, the current interrupt environment, and more.  It can then
261 lockdep can find a number of scenarios in which the system could, on rare
262 occasion, deadlock.  This kind of problem can be painful (for both
269 status of any operation (such as a memory allocation) which can fail.  The
275 The kernel provides a fault injection framework which can do exactly that,
278 fail; these failures can be restricted to a specific range of code.
284 Other kinds of errors can be found with the "sparse" static analysis tool.
285 With sparse, the programmer can be warned about confusion between
288 flags is expected, and so on.  Sparse must be installed separately (it can
290 distributor does not package it); it can then be run on the code by adding
294 variety of potential coding problems; it can also propose fixes for those
302 Blackfin development board handy, you can still perform the compilation
303 step.  A large set of cross compilers for x86 systems can be found at
341 specially-formatted comments; these comments can be extracted and formatted
346 comments for the future; indeed, this can be a useful activity for
348 information on how to create kerneldoc templates can be found in the file
371 programming interfaces, instead, are highly fluid and can be changed when
377 There are, of course, some catches.  API changes can be made, but they need
385 which is broken by the change.  For a widely-used function, this duty can
388 say, this can be a large job, so it is best to be sure that the
389 justification is solid.  Note that the Coccinelle tool can help with