On Thu, 20 Jan 2011, Robert Richter wrote:
Hi,
On 20.01.11 04:42:24, Will Deacon wrote:
Hi Ari,
Always allow backtrace when using oprofile on ARM, even if a PMU
isn't present.
Restores functionality originally introduced in
1b7b56982fdcd9d85effd76f3928cf5d6eb26155 by Richard Purdie.
Well spotted, I'd forgotten we still want this for timer mode.
Comments inline.
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index 8aa9744..a23e5ae 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -46,6 +46,7 @@ char *op_name_from_perf_id(void)
return NULL;
}
}
+#endif
static int report_trace(struct stackframe *frame, void *d)
{
@@ -109,6 +110,7 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
tail = user_backtrace(tail);
}
+#ifdef CONFIG_HW_PERF_EVENTS
Can you reorder the backtrace stuff so that we don't need the extra
#endif/#ifdef please?
I would like to go even further, see the diff below.
Thanks for comments, I can prepare a new patch. I think your patch below
has two typos but the idea was clear, please see comments below.
-Robert
---
arch/arm/oprofile/common.c | 45 ++++++++++++++++++++++++-------------------
1 files changed, 25 insertions(+), 20 deletions(-)
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index 8aa9744..916aa2e 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -47,18 +47,6 @@ char *op_name_from_perf_id(void)
}
}
-static int report_trace(struct stackframe *frame, void *d)
-{
- unsigned int *depth = d;
-
- if (*depth) {
- oprofile_add_trace(frame->pc);
- (*depth)--;
- }
-
- return *depth == 0;
-}
-
/*
* The registers we're interested in are at the end of the variable
* length saved register structure. The fp points at the end of this
@@ -91,6 +79,30 @@ static struct frame_tail* user_backtrace(struct frame_tail *tail)
return buftail[0].fp-1;
}
+#else
+
+static int oprofile_arch_init(struct oprofile_operations *ops)
+{
+ pr_info("oprofile: hardware counters not available\n");
+ return -ENODEV;
+}
+
+static void oprofile_arch_exit(void) { }
I guess you mean oprofile_perf_init and oprofile_perf_exit?
Also the user_backtrace and frame_tail need to be moved out from the
#ifdef.
+
+#endif /* CONFIG_HW_PERF_EVENTS */
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ unsigned int *depth = d;
+
+ if (*depth) {
+ oprofile_add_trace(frame->pc);
+ (*depth)--;
+ }
+
+ return *depth == 0;
+}
+
static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
{
struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
@@ -111,6 +123,7 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
+ /* provide backtrace support also in timer mode: */
ops->backtrace = arm_backtrace;
return oprofile_perf_init(ops);
@@ -120,11 +133,3 @@ void __exit oprofile_arch_exit(void)
{
oprofile_perf_exit();
}
-#else
-int __init oprofile_arch_init(struct oprofile_operations *ops)
-{
- pr_info("oprofile: hardware counters not available\n");
- return -ENODEV;
-}
-void __exit oprofile_arch_exit(void) {}
-#endif /* CONFIG_HW_PERF_EVENTS */
--
Ari
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