From: Jim Cromie <jim.cromie@gmail.com>
To: Jason Baron <jbaron@akamai.com>, linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, Jim Cromie <jim.cromie@gmail.com>
Subject: [RFC PATCH v5 01/28] dyndbg: avoid calling dyndbg_emit_prefix when it has no work
Date: Tue, 11 May 2021 12:50:30 -0600 [thread overview]
Message-ID: <20210511185057.3815777-2-jim.cromie@gmail.com> (raw)
In-Reply-To: <20210511185057.3815777-1-jim.cromie@gmail.com>
Wrap function in a static-inline one, which checks flags to avoid
calling the function unnecessarily.
And hoist its output-buffer initialization to the grand-caller, which
is already allocating the buffer on the stack, and can trivially
initialize it too.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
include/linux/dynamic_debug.h | 5 +++++
lib/dynamic_debug.c | 19 ++++++++++++-------
2 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index a57ee75342cf..dce631e678dd 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -32,6 +32,11 @@ struct _ddebug {
#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
#define _DPRINTK_FLAGS_INCL_TID (1<<4)
+
+#define _DPRINTK_FLAGS_INCL_ANY \
+ (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
+ _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID)
+
#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
#else
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c70d6347afa2..ede4a491ee87 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -586,13 +586,11 @@ static int remaining(int wrote)
return 0;
}
-static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
+static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
{
int pos_after_tid;
int pos = 0;
- *buf = '\0';
-
if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
if (in_interrupt())
pos += snprintf(buf + pos, remaining(pos), "<intr> ");
@@ -618,11 +616,18 @@ static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
return buf;
}
+static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
+{
+ if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
+ return __dynamic_emit_prefix(desc, buf);
+ return buf;
+}
+
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
{
va_list args;
struct va_format vaf;
- char buf[PREFIX_SIZE];
+ char buf[PREFIX_SIZE] = "";
BUG_ON(!descriptor);
BUG_ON(!fmt);
@@ -655,7 +660,7 @@ void __dynamic_dev_dbg(struct _ddebug *descriptor,
if (!dev) {
printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
} else {
- char buf[PREFIX_SIZE];
+ char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
dynamic_emit_prefix(descriptor, buf),
@@ -684,7 +689,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor,
vaf.va = &args;
if (dev && dev->dev.parent) {
- char buf[PREFIX_SIZE];
+ char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
"%s%s %s %s%s: %pV",
@@ -720,7 +725,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
vaf.va = &args;
if (ibdev && ibdev->dev.parent) {
- char buf[PREFIX_SIZE];
+ char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
"%s%s %s %s: %pV",
--
2.31.1
next prev parent reply other threads:[~2021-05-11 18:51 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 18:50 [RFC PATCH v5 00/28] dynamic debug diet plan Jim Cromie
2021-05-11 18:50 ` Jim Cromie [this message]
2021-05-11 18:50 ` [RFC PATCH v5 02/28] dyndbg: drop uninformative vpr_info Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 03/28] dyndbg: split struct _ddebug's display fields to new _ddebug_site Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 04/28] dyndbg: __init iterate over __dyndbg & __dyndbg_site in parallel Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 05/28] dyndbg: refactor part of ddebug_change to ddebug_match_site Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 06/28] dyndbg: accept null site in ddebug_match_site Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 07/28] dyndbg: hoist ->site out of ddebug_match_site Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 08/28] dyndbg: accept null site in ddebug_change Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 09/28] dyndbg: accept null site in dynamic_emit_prefix Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 10/28] dyndbg: accept null site in ddebug_proc_show Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 11/28] dyndbg: refactor ddebug_alter_site out of ddebug_change Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 12/28] dyndbg: allow deleting site info via control interface Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 13/28] dyndbg+module: expose ddebug_sites to modules Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 14/28] dyndbg: add ddebug_site(_get|_put) abstraction Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 15/28] dyndbg: ddebug_add_module avoid adding empty modules Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 16/28] dyndbg: add _index to struct _ddebug Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 17/28] dyndbg: prevent build bugs via -DNO_DYNAMIC_DEBUG_TABLE Jim Cromie
2021-05-12 14:55 ` Ard Biesheuvel
2021-05-12 18:03 ` jim.cromie
2021-05-11 18:50 ` [RFC PATCH v5 18/28] dyndbg: RFC - DEFINE_DYNAMIC_DEBUG_TABLE Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 19/28] dyndbg: RFC handle __dyndbg* sections in module.lds.h Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 20/28] dyndbg: ddebug_add_module() handle headers Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 21/28] dyndbg: validate ddebug_site_get invariants Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 22/28] dyndbg: fix NULL deref after deleting sites Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 23/28] dyndbg: dont show header records in control Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 24/28] dyndbg: make site pointer and checks on it optional (not quite) Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 25/28] dyndbg: swap WARN_ON for BUG_ON see what 0-day says Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 26/28] dyndbg: fixup protect header when deleting site Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 27/28] dyndbg: unionize _ddebug*_headers with struct _ddebug* Jim Cromie
2021-05-11 18:50 ` [RFC PATCH v5 28/28] dyndbg: RFC drop _ddebug.site pointer Jim Cromie
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