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perf callchain: Create an address space per thread

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The unw_addr_space_t in libunwind represents an address space to be used
for stack unwinding.  It doesn't need to be create/destory everytime to
unwind callchain (as in get_entries) and can have a same lifetime as
thread (unless exec called).

So move the address space construction/destruction logic to the thread
lifetime handling functions.  This is a preparation to enable caching in
the unwind library.

Note that it saves unw_addr_space_t object using thread__set_priv().  It
seems currently only used by perf trace and perf kvm stat commands which
don't use callchain.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jean Pihet <jean.pihet@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1412556363-26229-3-git-send-email-namhyung@kernel.org
[ Fixup unwind-libunwind.c missing CALLCHAIN_DWARF definition, added
  missing __maybe_unused on unused parameters in stubs at util/unwind.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim
2014-10-06 09:46:00 +09:00
committed by Arnaldo Carvalho de Melo
parent 0cdccac6fe
commit 66f066d899
3 changed files with 56 additions and 6 deletions
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39
tools/perf/util/unwind-libunwind.c
View File

@@ -24,6 +24,7 @@
#include <linux/list.h>
#include <libunwind.h>
#include <libunwind-ptrace.h>
#include "callchain.h"
#include "thread.h"
#include "session.h"
#include "perf_regs.h"
@@ -525,6 +526,35 @@ static unw_accessors_t accessors = {
.get_proc_name = get_proc_name,
};
int unwind__prepare_access(struct thread *thread)
{
unw_addr_space_t addr_space;
if (callchain_param.record_mode != CALLCHAIN_DWARF)
return 0;
addr_space = unw_create_addr_space(&accessors, 0);
if (!addr_space) {
pr_err("unwind: Can't create unwind address space.\n");
return -ENOMEM;
}
thread__set_priv(thread, addr_space);
return 0;
}
void unwind__finish_access(struct thread *thread)
{
unw_addr_space_t addr_space;
if (callchain_param.record_mode != CALLCHAIN_DWARF)
return;
addr_space = thread__priv(thread);
unw_destroy_addr_space(addr_space);
}
static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
void *arg, int max_stack)
{
@@ -532,11 +562,9 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
unw_cursor_t c;
int ret;
addr_space = unw_create_addr_space(&accessors, 0);
if (!addr_space) {
pr_err("unwind: Can't create unwind address space.\n");
return -ENOMEM;
}
addr_space = thread__priv(ui->thread);
if (addr_space == NULL)
return -1;
ret = unw_init_remote(&c, addr_space, ui);
if (ret)
@@ -549,7 +577,6 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
ret = ip ? entry(ip, ui->thread, ui->machine, cb, arg) : 0;
}
unw_destroy_addr_space(addr_space);
return ret;
}