From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Phil Auld <pauld@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Kate Carcia <kcarcia@redhat.com>,
Jonathan Corbet <corbet@lwn.net>, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
Clark Willaims <williams@redhat.com>,
John Kacur <jkacur@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, linux-doc@vger.kernel.org,
Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: [for-next][PATCH 18/24] trace: Add __print_ns_to_secs() and __print_ns_without_secs() helpers
Date: Sat, 26 Jun 2021 09:04:22 -0400 [thread overview]
Message-ID: <20210626130537.815513044@goodmis.org> (raw)
In-Reply-To: 20210626130404.033700863@goodmis.org
From: Steven Rostedt <rostedt@goodmis.org>
To have nanosecond output displayed in a more human readable format, its
nicer to convert it to a seconds format (XXX.YYYYYYYYY). The problem is that
to do so, the numbers must be divided by NSEC_PER_SEC, and moded too. But as
these numbers are 64 bit, this can not be done simply with '/' and '%'
operators, but must use do_div() instead.
Instead of performing the expensive do_div() in the hot path of the
tracepoint, it is more efficient to perform it during the output phase. But
passing in do_div() can confuse the parser, and do_div() doesn't work
exactly like a normal C function. It modifies the number in place, and we
don't want to modify the actual values in the ring buffer.
Two helper functions are now created:
__print_ns_to_secs() and __print_ns_without_secs()
They both take a value of nanoseconds, and the former will return that
number divided by NSEC_PER_SEC, and the latter will mod it with NSEC_PER_SEC
giving a way to print a nice human readable format:
__print_fmt("time=%llu.%09u",
__print_ns_to_secs(REC->nsec_val),
__print_ns_without_secs(REC->nsec_val))
Link: https://lkml.kernel.org/r/e503b903045496c4ccde52843e1e318b422f7a56.1624372313.git.bristot@redhat.com
Cc: Phil Auld <pauld@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Kate Carcia <kcarcia@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Clark Willaims <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/trace/trace_events.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 8268bf747d6f..acc17194c160 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -358,6 +358,21 @@ TRACE_MAKE_SYSTEM_STR();
trace_print_hex_dump_seq(p, prefix_str, prefix_type, \
rowsize, groupsize, buf, len, ascii)
+#undef __print_ns_to_secs
+#define __print_ns_to_secs(value) \
+ ({ \
+ u64 ____val = (u64)(value); \
+ do_div(____val, NSEC_PER_SEC); \
+ ____val; \
+ })
+
+#undef __print_ns_without_secs
+#define __print_ns_without_secs(value) \
+ ({ \
+ u64 ____val = (u64)(value); \
+ (u32) do_div(____val, NSEC_PER_SEC); \
+ })
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t \
@@ -736,6 +751,16 @@ static inline void ftrace_test_probe_##call(void) \
#undef __print_array
#undef __print_hex_dump
+/*
+ * The below is not executed in the kernel. It is only what is
+ * displayed in the print format for userspace to parse.
+ */
+#undef __print_ns_to_secs
+#define __print_ns_to_secs(val) (val) / 1000000000UL
+
+#undef __print_ns_without_secs
+#define __print_ns_without_secs(val) (val) % 1000000000UL
+
#undef TP_printk
#define TP_printk(fmt, args...) "\"" fmt "\", " __stringify(args)
--
2.30.2
next prev parent reply other threads:[~2021-06-26 13:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-26 13:04 [for-next][PATCH 00/24] tracing: Last minute updates for 5.14 Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 01/24] bootconfig: Change array value to use child node Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 02/24] bootconfig: Support mixing a value and subkeys under a key Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 03/24] tools/bootconfig: Support mixed value and subkey test cases Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 04/24] docs: bootconfig: Update for mixing value and subkeys Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 05/24] bootconfig: Share the checksum function with tools Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 06/24] tracing: Simplify the max length test when using the filtering temp buffer Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 07/24] tracing: Add better comments for the filtering temp buffer use case Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 08/24] tracing: Add tp_printk_stop_on_boot option Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 09/24] tracing: Have ftrace_dump_on_oops kernel parameter take numbers Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 10/24] bootconfig/tracing/ktest: Add ktest examples of testing bootconfig Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 11/24] trace/hwlat: Fix Clarks email Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 12/24] trace/hwlat: Implement the mode config option Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 13/24] trace/hwlat: Switch disable_migrate to mode none Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 14/24] trace/hwlat: Implement the per-cpu mode Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 15/24] trace: Add a generic function to read/write u64 values from tracefs Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 16/24] trace/hwlat: Use trace_min_max_param for width and window params Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 17/24] trace/hwlat: Remove printk from sampling loop Steven Rostedt
2021-06-26 13:04 ` Steven Rostedt [this message]
2021-06-26 13:04 ` [for-next][PATCH 19/24] tracing: Add LATENCY_FS_NOTIFY to define if latency_fsnotify() is defined Steven Rostedt
2021-07-20 19:19 ` Arnd Bergmann
2021-06-26 13:04 ` [for-next][PATCH 20/24] trace: Add osnoise tracer Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 21/24] trace: Add timerlat tracer Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 22/24] trace/hwlat: Protect kdata->kthread with get/put_online_cpus Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 23/24] trace/hwlat: Support hotplug operations Steven Rostedt
2021-06-26 13:04 ` [for-next][PATCH 24/24] trace/osnoise: " Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210626130537.815513044@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=alexandre.chartre@oracle.com \
--cc=bigeasy@linutronix.de \
--cc=bp@alien8.de \
--cc=bristot@redhat.com \
--cc=corbet@lwn.net \
--cc=hpa@zytor.com \
--cc=jkacur@redhat.com \
--cc=juri.lelli@redhat.com \
--cc=kcarcia@redhat.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=pauld@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).