Prev: drivers/net: Eliminate a NULL pointer dereference
Next: [PATCH 5/8] HWPOISON, hugetlb: maintain mce_bad_pages in handling hugepage error
From: Steven Rostedt on 27 May 2010 20:30
On Thu, 2010-05-27 at 18:14 -0500, Jason Wessel wrote:
> In systems with more than one processor it is desriable to look at the
> per cpu trace buffers.
>
> CC: Frederic Weisbecker <fweisbec(a)gmail.com>

> CC: Steven Rostedt <rostedt(a)goodmis.org>

Acked-by: Steven Rostedt <rostedt(a)goodmis.org>

-- Steve


> Signed-off-by: Jason Wessel <jason.wessel(a)windriver.com>
> ---
> kernel/trace/trace_kdb.c | 37 +++++++++++++++++++++++++++----------
> 1 files changed, 27 insertions(+), 10 deletions(-)
>
> diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
> index 44cbda2..7b8ecd7 100644
> --- a/kernel/trace/trace_kdb.c
> +++ b/kernel/trace/trace_kdb.c
> @@ -17,7 +17,7 @@
> #include "trace.h"
> #include "trace_output.h"
>
> -static void ftrace_dump_buf(int skip_lines)
> +static void ftrace_dump_buf(int skip_lines, long cpu_file)
> {
> /* use static because iter can be a bit big for the stack */
> static struct trace_iterator iter;
> @@ -44,13 +44,20 @@ static void ftrace_dump_buf(int skip_lines)
> iter.iter_flags |= TRACE_FILE_LAT_FMT;
> iter.pos = -1;
>
> - for_each_tracing_cpu(cpu) {
> - iter.buffer_iter[cpu] =
> + if (cpu_file == TRACE_PIPE_ALL_CPU) {
> + for_each_tracing_cpu(cpu) {
> + iter.buffer_iter[cpu] =
> ring_buffer_read_prepare(iter.tr->buffer, cpu);
> - ring_buffer_read_start(iter.buffer_iter[cpu]);
> - tracing_iter_reset(&iter, cpu);
> + ring_buffer_read_start(iter.buffer_iter[cpu]);
> + tracing_iter_reset(&iter, cpu);
> + }
> + } else {
> + iter.cpu_file = cpu_file;
> + iter.buffer_iter[cpu_file] =
> + ring_buffer_read_prepare(iter.tr->buffer, cpu_file);
> + ring_buffer_read_start(iter.buffer_iter[cpu_file]);
> + tracing_iter_reset(&iter, cpu_file);
> }
> -
> if (!trace_empty(&iter))
> trace_find_next_entry_inc(&iter);
> while (!trace_empty(&iter)) {
> @@ -91,9 +98,10 @@ out:
> static int kdb_ftdump(int argc, const char **argv)
> {
> int skip_lines = 0;
> + long cpu_file;
> char *cp;
>
> - if (argc > 1)
> + if (argc > 2)
> return KDB_ARGCOUNT;
>
> if (argc) {
> @@ -102,8 +110,17 @@ static int kdb_ftdump(int argc, const char **argv)
> skip_lines = 0;
> }
>
> + if (argc == 2) {
> + cpu_file = simple_strtol(argv[2], &cp, 0);
> + if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 ||
> + !cpu_online(cpu_file))
> + return KDB_BADINT;
> + } else {
> + cpu_file = TRACE_PIPE_ALL_CPU;
> + }
> +
> kdb_trap_printk++;
> - ftrace_dump_buf(skip_lines);
> + ftrace_dump_buf(skip_lines, cpu_file);
> kdb_trap_printk--;
>
> return 0;
> @@ -111,8 +128,8 @@ static int kdb_ftdump(int argc, const char **argv)
>
> static __init int kdb_ftrace_register(void)
> {
> - kdb_register_repeat("ftdump", kdb_ftdump, "", "Dump ftrace log",
> - 0, KDB_REPEAT_NONE);
> + kdb_register_repeat("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
> + "Dump ftrace log", 0, KDB_REPEAT_NONE);
> return 0;
> }
>


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: drivers/net: Eliminate a NULL pointer dereference
Next: [PATCH 5/8] HWPOISON, hugetlb: maintain mce_bad_pages in handling hugepage error