Use the user-provided kernel PID for uptime

* rootdir.c (get_boottime, get_idletime): replace KERNEL_PID with the
  opt_kernel_pid command-line option.
* main.c (argp): Document the change.

2 files changed, 4 insertions, 5 deletions

diff --git a/main.c b/main.c
index 94fc227d..3a976ccc 100644
--- a/main.c
+++ b/main.c
@@ -114,7 +114,8 @@ struct argp argp = {
 	"purposes.  If PID is omitted, \"self\" will point to init.  "
 	"(default: no self link)" },
     { "kernel-process", 'k', "PID", 0,
-	"Process identifier for the kernel, used to retreive its command line "
+	"Process identifier for the kernel, used to retreive its command "
+	"line, as well as the global up and idle times. "
 	"(default: 2)" },
     { "compatible", 'c', NULL, 0,
 	"Try to be compatible with the Linux procps utilities.  "
diff --git a/rootdir.c b/rootdir.c
index da068cf4..15ef8bce 100644
--- a/rootdir.c
+++ b/rootdir.c
@@ -38,8 +38,6 @@
    using them would require locking and as a consequence it would be
    more complicated, not simpler.  */
 
-#define KERNEL_PID 2
-
 
 /* Helper functions */
 
@@ -50,7 +48,7 @@ get_boottime (struct ps_context *pc, struct timeval *tv)
   struct proc_stat *ps;
   error_t err;
 
-  err = _proc_stat_create (KERNEL_PID, pc, &ps);
+  err = _proc_stat_create (opt_kernel_pid, pc, &ps);
   if (err)
     return err;
 
@@ -78,7 +76,7 @@ get_idletime (struct ps_context *pc, struct timeval *tv)
   error_t err;
   int i;
 
-  err = _proc_stat_create (KERNEL_PID, pc, &ps);
+  err = _proc_stat_create (opt_kernel_pid, pc, &ps);
   if (err)
     return err;