From 19063c776fe745fab11216422cf56489ee83b452 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 5 Aug 2010 09:22:23 -0500 Subject: [PATCH] ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump In systems with more than one processor it is desirable to look at the per cpu trace buffers. Signed-off-by: Jason Wessel Acked-by: Steven Rostedt CC: Frederic Weisbecker --- kernel/trace/trace_kdb.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 44cbda25b0a5..7b8ecd751d93 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; }