Messages in this thread | | | Date | Mon, 31 Jan 2022 10:17:25 -0800 | From | Roman Gushchin <> | Subject | Re: [PATCH v2 1/3] lib/vsprintf: Avoid redundant work with 0 size |
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On Sat, Jan 29, 2022 at 03:53:13PM -0500, Waiman Long wrote: > For *scnprintf(), vsnprintf() is always called even if the input size is > 0. That is a waste of time, so just return 0 in this case. > > Signed-off-by: Waiman Long <longman@redhat.com> > --- > lib/vsprintf.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > index 3b8129dd374c..a65df546fb06 100644 > --- a/lib/vsprintf.c > +++ b/lib/vsprintf.c > @@ -2895,13 +2895,15 @@ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) > { > int i; > > + if (!size) > + return 0; > + > i = vsnprintf(buf, size, fmt, args); > > if (likely(i < size)) > return i; > - if (size != 0) > - return size - 1; > - return 0; > + > + return size - 1; > } > EXPORT_SYMBOL(vscnprintf);
Acked-by: Roman Gushchin <guro@fb.com>
Thanks!
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