提交 97e7e4f3 编写于 作者: W Witold Baryluk 提交者: Steven Rostedt

tracing: optimization of branch tracer

Impact: better performance for if branch tracer

Use an array to count the hit and misses of a conditional instead
of using another conditional. This cuts down on saturation of branch
predictions and increases performance of modern pipelined architectures.
Signed-off-by: NWitold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
上级 af4617bd
......@@ -68,6 +68,7 @@ struct ftrace_branch_data {
unsigned long miss;
unsigned long hit;
};
unsigned long miss_hit[2];
};
};
......@@ -125,10 +126,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
.line = __LINE__, \
}; \
______r = !!(cond); \
if (______r) \
______f.hit++; \
else \
______f.miss++; \
______f.miss_hit[______r]++; \
______r; \
}))
#endif /* CONFIG_PROFILE_ALL_BRANCHES */
......
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