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| author | Jim Cromie <jim.cromie@gmail.com> | 2021-05-04 16:22:34 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-13 20:50:23 +0200 |
| commit | 640d1eaff2c09e382a23bd831094ebbfaa16fef5 (patch) | |
| tree | 3b081de7f657cbfb2aeeed57f1333c406f6afe1f /lib | |
| parent | ced081a436d21a7d34d4d42acb85058f9cf423f2 (diff) | |
| download | lwn-640d1eaff2c09e382a23bd831094ebbfaa16fef5.tar.gz lwn-640d1eaff2c09e382a23bd831094ebbfaa16fef5.zip | |
dyndbg: avoid calling dyndbg_emit_prefix when it has no work
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>
Link: https://lore.kernel.org/r/20210504222235.1033685-2-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/dynamic_debug.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 921d0a654243..398920403321 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", |