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author | Steven Rostedt <srostedt@redhat.com> | 2011-03-25 16:21:06 -0400 |
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committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-06-14 16:40:27 -0400 |
commit | 5078fc4d3e14f09eb52fa5e975729d1a873fafb0 (patch) | |
tree | 7825bdf3d87ee93d48ebc58949bc08ccc73b3fe1 /drivers | |
parent | c7983304c310103f270ac507d199f8614a61fdfd (diff) |
WARN_ON_SMP(): Add comment to explain ({0;})
The define to use ({0;}) for the !CONFIG_SMP case of WARN_ON_SMP()
can be confusing. As the WARN_ON_SMP() needs to be a nop when
CONFIG_SMP is not set, including all its parameters must not be
evaluated, and that it must work as both a stand alone statement
and inside an if condition, we define it to a funky ({0;}).
A simple "0" will not work as it causes gcc to give the warning that
the statement has no effect.
As this strange definition has raised a few eyebrows from some
major kernel developers, it is wise to document why we create such
a work of art.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
(cherry picked from commit ccd0d44fad38dc1bb4b26dcc7a30e9f2c3b36870)
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions