On Tue, 2018-08-28 at 11:24 -0700, Joe Perches wrote:
> On Tue, 2018-08-28 at 02:14 +0300, Alexey Dobriyan wrote:
> > Space savings -- 42 bytes!
> >
> > seq_puts 71 29 [-42]
> >
> > Signed-off-by: Alexey Dobriyan <adobri...@gmail.com>
> > ---
> > fs/seq_file.c | 9 +--------
> > 1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/fs/seq_file.c b/fs/seq_file.c
> > index 1dea7a8a5255..0c282a88a896 100644
> > --- a/fs/seq_file.c
> > +++ b/fs/seq_file.c
> > @@ -653,14 +653,7 @@ EXPORT_SYMBOL(seq_putc);
> >
> > void seq_puts(struct seq_file *m, const char *s)
> > {
> > - int len = strlen(s);
> > -
> > - if (m->count + len >= m->size) {
> > - seq_set_overflow(m);
> > - return;
> > - }
> > - memcpy(m->buf + m->count, s, len);
> > - m->count += len;
> > + seq_write(m, s, strlen(s));
> > }
> > EXPORT_SYMBOL(seq_puts);
> >
>
> If execution speed is really an issue, as
> almost all of the uses are for const strings,
> why not use a #define and avoid the runtime
> cost of strlen where possible.
fyi: an x86-64 defconfig increases < .5 kb and
presumably is faster for most all seq_puts uses
$ size vmlinux.new vmlinux.old
text data bss dec hex
filename
17342316 4982128 999628 23324072 163e5a8
vmlinux.new
17341857 4982128 999628 23323613 163e3dd
vmlinux.old
with
---
fs/seq_file.c | 13 -------------
include/linux/seq_file.h | 2 +-
2 files changed, 1 insertion(+), 14 deletions(-)
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 1dea7a8a5255..97d474b6788e 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -651,19 +651,6 @@ void seq_putc(struct seq_file *m, char c)
}
EXPORT_SYMBOL(seq_putc);
-void seq_puts(struct seq_file *m, const char *s)
-{
- int len = strlen(s);
-
- if (m->count + len >= m->size) {
- seq_set_overflow(m);
- return;
- }
- memcpy(m->buf + m->count, s, len);
- m->count += len;
-}
-EXPORT_SYMBOL(seq_puts);
-
/**
* A helper routine for putting decimal numbers without rich format of
printf().
* only 'unsigned long long' is supported.
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index a121982af0f5..722028805df6 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -117,7 +117,7 @@ void seq_vprintf(struct seq_file *m, const char *fmt,
va_list args);
__printf(2, 3)
void seq_printf(struct seq_file *m, const char *fmt, ...);
void seq_putc(struct seq_file *m, char c);
-void seq_puts(struct seq_file *m, const char *s);
+#define seq_puts(m, s) seq_write(m, s, strlen(s))
void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
unsigned long long num, unsigned int width);
void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
