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| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2018-10-29 23:35:42 +0100 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-12-22 08:21:06 -0500 |
| commit | bea6957d5cd7cbb327083d3bcf080133ee63ef65 (patch) | |
| tree | 459cde1b613bb3f0263a74b405e70ba2361b78a5 /kernel/trace | |
| parent | cc9f59fb3bc455984404dbab8be16f156a47d023 (diff) | |
| download | linux-bea6957d5cd7cbb327083d3bcf080133ee63ef65.tar.gz | |
tracing: Simplify printf'ing in seq_print_sym
trace_seq_printf(..., "%s", ...) can be done with trace_seq_puts() instead, avoiding printf overhead. In the second instance, the string we're copying was just created from an snprintf() to a stack buffer, so we might as well do that printf directly. This naturally leads to moving the declaration of the str buffer inside the CONFIG_KALLSYMS guard, which in turn will make gcc inline the function for !CONFIG_KALLSYMS (it only has a single caller, but the huge stack frame seems to make gcc not inline it for CONFIG_KALLSYMS). Link: http://lkml.kernel.org/r/20181029223542.26175-4-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_output.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index f06fb899b746..54373d93e251 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -341,8 +341,8 @@ static inline const char *kretprobed(const char *name) static void seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) { - char str[KSYM_SYMBOL_LEN]; #ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; const char *name; if (offset) @@ -352,12 +352,11 @@ seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) name = kretprobed(str); if (name && strlen(name)) { - trace_seq_printf(s, "%s", name); + trace_seq_puts(s, name); return; } #endif - snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address); - trace_seq_printf(s, "%s", str); + trace_seq_printf(s, "0x%08lx", address); } #ifndef CONFIG_64BIT |