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authorRobert Richter <robert.richter@amd.com>2011-10-11 19:11:08 +0400
committerRobert Richter <robert.richter@amd.com>2011-11-04 19:27:18 +0400
commitdcfce4a095932e6e95d83ad982be3609947963bc (patch)
tree2808b7cbdb57deab25cc1cd847fd0f9ffa058f92 /drivers/oprofile/oprof.c
parent75c43a20b220f885c39ffa7cdbbb1191e257a9a9 (diff)
downloadlinux-dcfce4a095932e6e95d83ad982be3609947963bc.tar.xz
oprofile, x86: Reimplement nmi timer mode using perf event
The legacy x86 nmi watchdog code was removed with the implementation of the perf based nmi watchdog. This broke Oprofile's nmi timer mode. To run nmi timer mode we relied on a continuous ticking nmi source which the nmi watchdog provided. The nmi tick was no longer available and current watchdog can not be used anymore since it runs with very long periods in the range of seconds. This patch reimplements the nmi timer mode using a perf counter nmi source. V2: * removing pr_info() * fix undefined reference to `__udivdi3' for 32 bit build * fix section mismatch of .cpuinit.data:nmi_timer_cpu_nb * removed nmi timer setup in arch/x86 * implemented function stubs for op_nmi_init/exit() * made code more readable in oprofile_init() V3: * fix architectural initialization in oprofile_init() * fix CONFIG_OPROFILE_NMI_TIMER dependencies Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Robert Richter <robert.richter@amd.com>
Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r--drivers/oprofile/oprof.c24
1 files changed, 11 insertions, 13 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index f7cd06967aed..ed2c3ec07024 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -246,26 +246,24 @@ static int __init oprofile_init(void)
int err;
/* always init architecture to setup backtrace support */
+ timer_mode = 0;
err = oprofile_arch_init(&oprofile_ops);
+ if (!err) {
+ if (!timer && !oprofilefs_register())
+ return 0;
+ oprofile_arch_exit();
+ }
- timer_mode = err || timer; /* fall back to timer mode on errors */
- if (timer_mode) {
- if (!err)
- oprofile_arch_exit();
+ /* setup timer mode: */
+ timer_mode = 1;
+ /* no nmi timer mode if oprofile.timer is set */
+ if (timer || op_nmi_timer_init(&oprofile_ops)) {
err = oprofile_timer_init(&oprofile_ops);
if (err)
return err;
}
- err = oprofilefs_register();
- if (!err)
- return 0;
-
- /* failed */
- if (!timer_mode)
- oprofile_arch_exit();
-
- return err;
+ return oprofilefs_register();
}