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| author |   Steven Rostedt <rostedt@goodmis.org> | 2008-10-30 16:08:33 -0400 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2008-10-30 21:30:09 +0100 |
| commit | b807c3d0f8e39ed7cbbbe6da162650e305e8de15 (patch) | |
| tree | 59d2d75f221099bf5df7d6bcb71eaa63b6f424e8 /arch/x86 | |
| parent | ftrace: nmi safe code modification (diff) | |
| download | linux-dev-b807c3d0f8e39ed7cbbbe6da162650e305e8de15.tar.xz linux-dev-b807c3d0f8e39ed7cbbbe6da162650e305e8de15.zip | |
ftrace: nmi update statistics
Impact: add more debug info to /debugfs/tracing/dyn_ftrace_total_info
This patch adds dynamic ftrace NMI update statistics to the
/debugfs/tracing/dyn_ftrace_total_info stat file.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index fe5f859130b5..6685b0fc1b44 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -91,6 +91,19 @@ static int mod_code_write; static void *mod_code_ip; static void *mod_code_newcode; +static int nmi_wait_count; +static atomic_t nmi_update_count; + +int ftrace_arch_read_dyn_info(char *buf, int size) +{ + int r; + + r = snprintf(buf, size, "%u %u", + nmi_wait_count, + atomic_read(&nmi_update_count)); + return r; +} + static void ftrace_mod_code(void) { /* @@ -109,8 +122,10 @@ void ftrace_nmi_enter(void) atomic_inc(&in_nmi); /* Must have in_nmi seen before reading write flag */ smp_mb(); - if (mod_code_write) + if (mod_code_write) { ftrace_mod_code(); + atomic_inc(&nmi_update_count); + } } void ftrace_nmi_exit(void) @@ -122,8 +137,15 @@ void ftrace_nmi_exit(void) static void wait_for_nmi(void) { - while (atomic_read(&in_nmi)) + int waited = 0; + + while (atomic_read(&in_nmi)) { + waited = 1; cpu_relax(); + } + + if (waited) + nmi_wait_count++; } static int |