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Diffstat (limited to 'include/linux/compiler-gcc4.h')
| -rw-r--r-- | include/linux/compiler-gcc4.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index a03e9398a6c..14f7494280f 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -23,3 +23,21 @@ * code */ #define uninitialized_var(x) x = x + +#if !(__GNUC__ == 4 && __GNUC_MINOR__ < 3) +/* Mark functions as cold. gcc will assume any path leading to a call + to them will be unlikely. This means a lot of manual unlikely()s + are unnecessary now for any paths leading to the usual suspects + like BUG(), printk(), panic() etc. [but let's keep them for now for + older compilers] + + Early snapshots of gcc 4.3 don't support this and we can't detect this + in the preprocessor, but we can live with this because they're unreleased. + Maketime probing would be overkill here. + + gcc also has a __attribute__((__hot__)) to move hot functions into + a special section, but I don't see any sense in this right now in + the kernel context */ +#define __cold __attribute__((__cold__)) + +#endif |