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perf: Generalize some arch callchain code

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- Most archs use one callchain buffer per cpu, except x86 that needs
  to deal with NMIs. Provide a default perf_callchain_buffer()
  implementation that x86 overrides.

- Centralize all the kernel/user regs handling and invoke new arch
  handlers from there: perf_callchain_user() / perf_callchain_kernel()
  That avoid all the user_mode(), current->mm checks and so...

- Invert some parameters in perf_callchain_*() helpers: entry to the
  left, regs to the right, following the traditional (dst, src).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Borislav Petkov <bp@amd64.org>
This commit is contained in:
Frederic Weisbecker
2010-06-30 23:03:51 +02:00
parent 70791ce9ba
commit 56962b4449
7 changed files with 90 additions and 180 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/arm/kernel/perf_event.c
+4 -39
View File
@@ -3044,17 +3044,13 @@ user_backtrace(struct frame_tail *tail,
return buftail.fp - 1;
}
static void
perf_callchain_user(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct frame_tail *tail;
perf_callchain_store(entry, PERF_CONTEXT_USER);
if (!user_mode(regs))
regs = task_pt_regs(current);
tail = (struct frame_tail *)regs->ARM_fp - 1;
while (tail && !((unsigned long)tail & 0x3))
@@ -3075,9 +3071,8 @@ callchain_trace(struct stackframe *fr,
return 0;
}
static void
perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
void
perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct stackframe fr;
@@ -3088,33 +3083,3 @@ perf_callchain_kernel(struct pt_regs *regs,
fr.pc = regs->ARM_pc;
walk_stackframe(&fr, callchain_trace, entry);
}
static void
perf_do_callchain(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
if (!is_user)
perf_callchain_kernel(regs, entry);
if (current->mm)
perf_callchain_user(regs, entry);
}
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
struct perf_callchain_entry *
perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry);
entry->nr = 0;
perf_do_callchain(regs, entry);
return entry;
}