Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756649Ab2JKX3H (ORCPT ); Thu, 11 Oct 2012 19:29:07 -0400 Received: from mail-vc0-f202.google.com ([209.85.220.202]:57047 "EHLO mail-vc0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622Ab2JKX2D (ORCPT ); Thu, 11 Oct 2012 19:28:03 -0400 From: David Sharp To: linux-kernel@vger.kernel.org Cc: David Sharp , Steven Rostedt , Masami Hiramatsu Subject: [PATCH v6 3/6] tracing: Format non-nanosec times from tsc clock without a decimal point. Date: Thu, 11 Oct 2012 16:27:53 -0700 Message-Id: <1349998076-15495-4-git-send-email-dhsharp@google.com> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1349998076-15495-1-git-send-email-dhsharp@google.com> References: <1349998076-15495-1-git-send-email-dhsharp@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9494 Lines: 274 With the addition of the "tsc" clock, formatting timestamps to look like fractional seconds is misleading. Mark clocks as either in nanoseconds or not, and format non-nanosecond timestamps as decimal integers. Tested: $ cd /sys/kernel/debug/tracing/ $ cat trace_clock [local] global tsc $ echo sched_switch > set_event $ echo 1 > tracing_enabled ; sleep 0.0005 ; echo 0 > tracing_enabled $ cat trace -0 [000] 6330.555552: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120 sleep-29964 [000] 6330.555628: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120 ... $ echo 1 > options/latency-format $ cat trace -0 0 4104553247us+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120 sleep-29964 0 4104553322us+: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120 ... $ echo tsc > trace_clock $ cat trace $ echo 1 > tracing_enabled ; sleep 0.0005 ; echo 0 > tracing_enabled $ echo 0 > options/latency-format $ cat trace -0 [000] 16490053398357: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120 sleep-31128 [000] 16490053588518: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120 ... echo 1 > options/latency-format $ cat trace -0 0 91557653238+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120 sleep-31128 0 91557843399+: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120 ... v2: Move arch-specific bits out of generic code. v4: Fix x86_32 build due to 64-bit division. Google-Bug-Id: 6980623 Signed-off-by: David Sharp Cc: Steven Rostedt Cc: Masami Hiramatsu --- arch/x86/include/asm/trace_clock.h | 2 +- include/linux/ftrace_event.h | 6 +++ kernel/trace/trace.c | 15 +++++- kernel/trace/trace.h | 4 -- kernel/trace/trace_output.c | 80 ++++++++++++++++++++++++----------- 5 files changed, 74 insertions(+), 33 deletions(-) diff --git a/arch/x86/include/asm/trace_clock.h b/arch/x86/include/asm/trace_clock.h index 7ee0d8c..45e17f5 100644 --- a/arch/x86/include/asm/trace_clock.h +++ b/arch/x86/include/asm/trace_clock.h @@ -9,7 +9,7 @@ extern u64 notrace trace_clock_x86_tsc(void); # define ARCH_TRACE_CLOCKS \ - { trace_clock_x86_tsc, "x86-tsc" }, + { trace_clock_x86_tsc, "x86-tsc", .in_ns = 0 }, #endif diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 642928c..c760670 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -86,6 +86,12 @@ struct trace_iterator { cpumask_var_t started; }; +enum trace_iter_flags { + TRACE_FILE_LAT_FMT = 1, + TRACE_FILE_ANNOTATE = 2, + TRACE_FILE_TIME_IN_NS = 4, +}; + struct trace_event; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4e26df3..cff3427 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -476,10 +476,11 @@ static const char *trace_options[] = { static struct { u64 (*func)(void); const char *name; + int in_ns; /* is this clock in nanoseconds? */ } trace_clocks[] = { - { trace_clock_local, "local" }, - { trace_clock_global, "global" }, - { trace_clock_counter, "counter" }, + { trace_clock_local, "local", 1 }, + { trace_clock_global, "global", 1 }, + { trace_clock_counter, "counter", 0 }, ARCH_TRACE_CLOCKS }; @@ -2425,6 +2426,10 @@ __tracing_open(struct inode *inode, struct file *file) if (ring_buffer_overruns(iter->tr->buffer)) iter->iter_flags |= TRACE_FILE_ANNOTATE; + /* Output in nanoseconds only if we are using a clock in nanoseconds. */ + if (trace_clocks[trace_clock_id].in_ns) + iter->iter_flags |= TRACE_FILE_TIME_IN_NS; + /* stop the trace while dumping */ tracing_stop(); @@ -3324,6 +3329,10 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) if (trace_flags & TRACE_ITER_LATENCY_FMT) iter->iter_flags |= TRACE_FILE_LAT_FMT; + /* Output in nanoseconds only if we are using a clock in nanoseconds. */ + if (trace_clocks[trace_clock_id].in_ns) + iter->iter_flags |= TRACE_FILE_TIME_IN_NS; + iter->cpu_file = cpu_file; iter->tr = &global_trace; mutex_init(&iter->mutex); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 55e1f7f..84fefed 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -409,10 +409,6 @@ void tracing_start_sched_switch_record(void); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); int is_tracing_stopped(void); -enum trace_file_type { - TRACE_FILE_LAT_FMT = 1, - TRACE_FILE_ANNOTATE = 2, -}; extern cpumask_var_t __read_mostly tracing_buffer_mask; diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 123b189..c8d2a60 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -610,24 +610,56 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) return trace_print_lat_fmt(s, entry); } -static unsigned long preempt_mark_thresh = 100; +static unsigned long preempt_mark_thresh_us = 100; static int -lat_print_timestamp(struct trace_seq *s, u64 abs_usecs, - unsigned long rel_usecs) +lat_print_timestamp(struct trace_iterator *iter, u64 next_ts) { - return trace_seq_printf(s, " %4lldus%c: ", abs_usecs, - rel_usecs > preempt_mark_thresh ? '!' : - rel_usecs > 1 ? '+' : ' '); + unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE; + unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS; + unsigned long long abs_ts = iter->ts - iter->tr->time_start; + unsigned long long rel_ts = next_ts - iter->ts; + struct trace_seq *s = &iter->seq; + int ret; + + if (in_ns) { + abs_ts = ns2usecs(abs_ts); + rel_ts = ns2usecs(rel_ts); + } + + if (verbose && in_ns) { + unsigned long abs_msec = abs_ts; + unsigned long abs_usec = do_div(abs_msec, USEC_PER_MSEC); + unsigned long rel_msec = rel_ts; + unsigned long rel_usec = do_div(rel_msec, USEC_PER_MSEC); + + ret = trace_seq_printf( + s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ", + ns2usecs(iter->ts), + abs_msec, abs_usec, + rel_msec, rel_usec); + } else if (verbose && !in_ns) { + ret = trace_seq_printf( + s, "[%016llx] %lld (+%lld): ", + iter->ts, abs_ts, rel_ts); + } else if (!verbose && in_ns) { + ret = trace_seq_printf( + s, " %4lldus%c: ", + abs_ts, + rel_ts > preempt_mark_thresh_us ? '!' : + rel_ts > 1 ? '+' : ' '); + } else { /* !verbose && !in_ns */ + ret = trace_seq_printf(s, " %4lld: ", abs_ts); + } + return ret; } int trace_print_context(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry = iter->ent; - unsigned long long t = ns2usecs(iter->ts); - unsigned long usec_rem = do_div(t, USEC_PER_SEC); - unsigned long secs = (unsigned long)t; + unsigned long long t; + unsigned long secs, usec_rem; char comm[TASK_COMM_LEN]; int ret; @@ -644,8 +676,13 @@ int trace_print_context(struct trace_iterator *iter) return 0; } - return trace_seq_printf(s, " %5lu.%06lu: ", - secs, usec_rem); + if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) { + t = ns2usecs(iter->ts); + usec_rem = do_div(t, USEC_PER_SEC); + secs = (unsigned long)t; + return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem); + } else + return trace_seq_printf(s, " %12llu: ", iter->ts); } int trace_print_lat_context(struct trace_iterator *iter) @@ -659,36 +696,29 @@ int trace_print_lat_context(struct trace_iterator *iter) *next_entry = trace_find_next_entry(iter, NULL, &next_ts); unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); - unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start); - unsigned long rel_usecs; /* Restore the original ent_size */ iter->ent_size = ent_size; if (!next_entry) next_ts = iter->ts; - rel_usecs = ns2usecs(next_ts - iter->ts); if (verbose) { char comm[TASK_COMM_LEN]; trace_find_cmdline(entry->pid, comm); - ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]" - " %ld.%03ldms (+%ld.%03ldms): ", comm, - entry->pid, iter->cpu, entry->flags, - entry->preempt_count, iter->idx, - ns2usecs(iter->ts), - abs_usecs / USEC_PER_MSEC, - abs_usecs % USEC_PER_MSEC, - rel_usecs / USEC_PER_MSEC, - rel_usecs % USEC_PER_MSEC); + ret = trace_seq_printf( + s, "%16s %5d %3d %d %08x %08lx ", + comm, entry->pid, iter->cpu, entry->flags, + entry->preempt_count, iter->idx); } else { ret = lat_print_generic(s, entry, iter->cpu); - if (ret) - ret = lat_print_timestamp(s, abs_usecs, rel_usecs); } + if (ret) + ret = lat_print_timestamp(iter, next_ts); + return ret; } -- 1.7.7.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/