diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-03-18 11:03:19 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-18 12:10:17 +0300 |
| commit | 2c7eea4c62ba090b7f4583c3d7337ea0019be900 (patch) | |
| tree | 2a85739caeef13035316d47f61cab11f3a91660f /kernel/trace/trace.c | |
| parent | 18aecd362a1c991fbf5f7919ae051a77532ba2f8 (diff) | |
| download | linux-2c7eea4c62ba090b7f4583c3d7337ea0019be900.tar.xz | |
tracing: replace the crude (unsigned) -1 hackery
Impact: cleanup
The command line recorder uses (unsigned) -1 to mark non mapped
entries in the pid to command line maps. The validity check is
completely unintuitive: idx >= SAVED_CMDLINES
There is no need for such casting games. Use a constant to mark
unmapped entries and check for that constant to make the code readable
and understandable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7b6043ea256e..ca673c475687 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -633,6 +633,7 @@ void tracing_reset_online_cpus(struct trace_array *tr) } #define SAVED_CMDLINES 128 +#define NO_CMDLINE_MAP UINT_MAX static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; @@ -644,8 +645,8 @@ static atomic_t trace_record_cmdline_disabled __read_mostly; static void trace_init_cmdlines(void) { - memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); - memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); + memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); + memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); cmdline_idx = 0; } @@ -753,12 +754,12 @@ static void trace_save_cmdline(struct task_struct *tsk) return; idx = map_pid_to_cmdline[tsk->pid]; - if (idx >= SAVED_CMDLINES) { + if (idx == NO_CMDLINE_MAP) { idx = (cmdline_idx + 1) % SAVED_CMDLINES; map = map_cmdline_to_pid[idx]; - if (map <= PID_MAX_DEFAULT) - map_pid_to_cmdline[map] = (unsigned)-1; + if (map != NO_CMDLINE_MAP) + map_pid_to_cmdline[map] = NO_CMDLINE_MAP; map_pid_to_cmdline[tsk->pid] = idx; @@ -786,7 +787,7 @@ void trace_find_cmdline(int pid, char comm[]) __raw_spin_lock(&trace_cmdline_lock); map = map_pid_to_cmdline[pid]; - if (map >= SAVED_CMDLINES) + if (map == NO_CMDLINE_MAP) goto out; strcpy(comm, saved_cmdlines[map]); |