From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162193AbbKEOnw (ORCPT ); Thu, 5 Nov 2015 09:43:52 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:36192 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162179AbbKEOns (ORCPT ); Thu, 5 Nov 2015 09:43:48 -0500 Date: Thu, 5 Nov 2015 23:43:34 +0900 From: Namhyung Kim To: Tom Zanussi Cc: rostedt@goodmis.org, daniel.wagner@bmw-carit.de, masami.hiramatsu.pt@hitachi.com, josh@joshtriplett.org, andi@firstfloor.org, mathieu.desnoyers@efficios.com, peterz@infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/28] tracing: 'hist' triggers Message-ID: <20151105144334.GA28273@danjae.kornet> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tom, I implemented 'log2' modifier on top of your v11 patchset. Could you please take a look at this? >>From 5fc74778b9af5e4e121a0563fb8e54e8f495ca29 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 5 Nov 2015 23:34:05 +0900 Subject: [PATCH] tracing: Add hist trigger 'log2' modifier Allow users to have numeric fields displayed as log2 values in case value range is very wide by appending '.log2' to field names. For example, # echo 'hist:key=bytes_req' > kmalloc/trigger # cat kmalloc/hist { bytes_req: 504 } hitcount: 1 { bytes_req: 11 } hitcount: 1 { bytes_req: 104 } hitcount: 1 { bytes_req: 48 } hitcount: 1 { bytes_req: 2048 } hitcount: 1 { bytes_req: 4096 } hitcount: 1 { bytes_req: 240 } hitcount: 1 { bytes_req: 392 } hitcount: 1 { bytes_req: 13 } hitcount: 1 { bytes_req: 28 } hitcount: 1 { bytes_req: 12 } hitcount: 1 { bytes_req: 64 } hitcount: 2 { bytes_req: 128 } hitcount: 2 { bytes_req: 32 } hitcount: 2 { bytes_req: 8 } hitcount: 11 { bytes_req: 10 } hitcount: 13 { bytes_req: 24 } hitcount: 25 { bytes_req: 160 } hitcount: 29 { bytes_req: 16 } hitcount: 33 { bytes_req: 80 } hitcount: 36 When using '.log2' modifier, the output looks like: # echo 'hist:key=bytes_req.log2' > kmalloc/trigger # cat kmalloc/hist { bytes_req: ~ 2^12 } hitcount: 1 { bytes_req: ~ 2^11 } hitcount: 1 { bytes_req: ~ 2^9 } hitcount: 2 { bytes_req: ~ 2^6 } hitcount: 3 { bytes_req: ~ 2^3 } hitcount: 13 { bytes_req: ~ 2^5 } hitcount: 19 { bytes_req: ~ 2^8 } hitcount: 49 { bytes_req: ~ 2^7 } hitcount: 57 { bytes_req: ~ 2^4 } hitcount: 74 Cc: Tom Zanussi Cc: Masami Hiramatsu Signed-off-by: Namhyung Kim --- kernel/trace/trace.c | 1 + kernel/trace/trace_events_hist.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 74f95745acbc..542486468707 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3837,6 +3837,7 @@ static const char readme_msg[] = "\t .sym-offset display an address as a symbol and offset\n" "\t .execname display a common_pid as a program name\n" "\t .syscall display a syscall id as a syscall name\n\n" + "\t .log2 display log2 value rather than raw number\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index b040ebefcd64..20a17fdb3fe6 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -68,6 +68,13 @@ static u64 hist_field_pstring(struct hist_field *hist_field, void *event) return (u64)(unsigned long)*addr; } +static u64 hist_field_log2(struct hist_field *hist_field, void *event) +{ + u64 val = *(u64 *)(event + hist_field->field->offset); + + return (u64) ilog2(roundup_pow_of_two(val)); +} + #define DEFINE_HIST_FIELD_FN(type) \ static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ { \ @@ -103,6 +110,7 @@ enum hist_field_flags { HIST_FIELD_EXECNAME = 64, HIST_FIELD_SYSCALL = 128, HIST_FIELD_STACKTRACE = 256, + HIST_FIELD_LOG2 = 512, }; struct hist_trigger_attrs { @@ -349,6 +357,11 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (flags & HIST_FIELD_LOG2) { + hist_field->fn = hist_field_log2; + goto out; + } + if (is_string_field(field)) { flags |= HIST_FIELD_STRING; @@ -500,6 +513,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_EXECNAME; else if (!strcmp(field_str, "syscall")) flags |= HIST_FIELD_SYSCALL; + else if (!strcmp(field_str, "log2")) + flags |= HIST_FIELD_LOG2; else { ret = -EINVAL; goto out; @@ -942,6 +957,9 @@ hist_trigger_entry_print(struct seq_file *m, key + key_field->offset, HIST_STACKTRACE_DEPTH); multiline = true; + } else if (key_field->flags & HIST_FIELD_LOG2) { + seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name, + *(u64 *)(key + key_field->offset)); } else if (key_field->flags & HIST_FIELD_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); -- 2.6.2