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authorNicolas Pitre <nico@cam.org>2008-04-24 01:31:46 -0400
committerLennert Buytenhek <buytenh@marvell.com>2008-06-22 22:44:36 +0200
commitf76e9154736e9ab47b64940d0062f19c80225b7f (patch)
treeeb8a909667362fc552894d7987ff3e57ade4fa0f
parentb0bfcce930bca38af056662e598991cb393eaa4a (diff)
[ARM] latencytop support
Available for !SMP only at the moment. From Russell: |Basically, if a thread is running on a CPU, thread_saved_fp() is invalid. |So, the question is: what guarantees do we have here that 'tsk' is not |running on another CPU? Signed-off-by: Nicolas Pitre <nico@marvell.com> Tested-by: Lennert Buytenhek <buytenh@marvell.com> Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
-rw-r--r--arch/arm/Kconfig5
-rw-r--r--arch/arm/kernel/stacktrace.c34
2 files changed, 35 insertions, 4 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b786e68914d..a91b9ac9a0e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -84,6 +84,11 @@ config STACKTRACE_SUPPORT
bool
default y
+config HAVE_LATENCYTOP_SUPPORT
+ bool
+ depends on !SMP
+ default y
+
config LOCKDEP_SUPPORT
bool
default y
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index ae31deb2d06..90e0c35ae60 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -36,6 +36,7 @@ EXPORT_SYMBOL(walk_stackframe);
#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
struct stack_trace *trace;
+ unsigned int no_sched_functions;
unsigned int skip;
};
@@ -43,27 +44,52 @@ static int save_trace(struct stackframe *frame, void *d)
{
struct stack_trace_data *data = d;
struct stack_trace *trace = data->trace;
+ unsigned long addr = frame->lr;
+ if (data->no_sched_functions && in_sched_functions(addr))
+ return 0;
if (data->skip) {
data->skip--;
return 0;
}
- trace->entries[trace->nr_entries++] = frame->lr;
+ trace->entries[trace->nr_entries++] = addr;
return trace->nr_entries >= trace->max_entries;
}
-void save_stack_trace(struct stack_trace *trace)
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
struct stack_trace_data data;
unsigned long fp, base;
data.trace = trace;
data.skip = trace->skip;
- base = (unsigned long)task_stack_page(current);
- asm("mov %0, fp" : "=r" (fp));
+ base = (unsigned long)task_stack_page(tsk);
+
+ if (tsk != current) {
+#ifdef CONFIG_SMP
+ /*
+ * What guarantees do we have here that 'tsk'
+ * is not running on another CPU?
+ */
+ BUG();
+#else
+ data.no_sched_functions = 1;
+ fp = thread_saved_fp(tsk);
+#endif
+ } else {
+ data.no_sched_functions = 0;
+ asm("mov %0, fp" : "=r" (fp));
+ }
walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ save_stack_trace_tsk(current, trace);
}
#endif