diff mbox series

lib/find: optimize find_*_bit_wrap

Message ID 20231028190530.286300-1-yury.norov@gmail.com
State New
Headers
Series lib/find: optimize find_*_bit_wrap |

Commit Message

Yury Norov Oct. 28, 2023, 7:05 p.m. UTC 
  When an offset is 0, there's no need to search a bitmap from the
beginning after the 1st search failed, because each bit has already
been tested.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 include/linux/find.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Yury Norov Nov. 10, 2023, 2:21 a.m. UTC | #1 
Ping?

On Sat, Oct 28, 2023 at 12:05:29PM -0700, Yury Norov wrote:
> When an offset is 0, there's no need to search a bitmap from the
> beginning after the 1st search failed, because each bit has already
> been tested.
> 
> Signed-off-by: Yury Norov <yury.norov@gmail.com>
> ---
>  include/linux/find.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/find.h b/include/linux/find.h
> index 5e4f39ef2e72..241b6d028eda 100644
> --- a/include/linux/find.h
> +++ b/include/linux/find.h
> @@ -405,7 +405,7 @@ unsigned long find_next_and_bit_wrap(const unsigned long *addr1,
>  {
>  	unsigned long bit = find_next_and_bit(addr1, addr2, size, offset);
>  
> -	if (bit < size)
> +	if (bit < size || offset == 0)
>  		return bit;
>  
>  	bit = find_first_and_bit(addr1, addr2, offset);
> @@ -427,7 +427,7 @@ unsigned long find_next_bit_wrap(const unsigned long *addr,
>  {
>  	unsigned long bit = find_next_bit(addr, size, offset);
>  
> -	if (bit < size)
> +	if (bit < size || offset == 0)
>  		return bit;
>  
>  	bit = find_first_bit(addr, offset);
> -- 
> 2.39.2
Yury Norov Dec. 3, 2023, 6:25 p.m. UTC | #2 
OK, taking in bitmap-for-next

On Thu, Nov 09, 2023 at 06:21:18PM -0800, Yury Norov wrote:
> Ping?
> 
> On Sat, Oct 28, 2023 at 12:05:29PM -0700, Yury Norov wrote:
> > When an offset is 0, there's no need to search a bitmap from the
> > beginning after the 1st search failed, because each bit has already
> > been tested.
> > 
> > Signed-off-by: Yury Norov <yury.norov@gmail.com>
> > ---
> >  include/linux/find.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/linux/find.h b/include/linux/find.h
> > index 5e4f39ef2e72..241b6d028eda 100644
> > --- a/include/linux/find.h
> > +++ b/include/linux/find.h
> > @@ -405,7 +405,7 @@ unsigned long find_next_and_bit_wrap(const unsigned long *addr1,
> >  {
> >  	unsigned long bit = find_next_and_bit(addr1, addr2, size, offset);
> >  
> > -	if (bit < size)
> > +	if (bit < size || offset == 0)
> >  		return bit;
> >  
> >  	bit = find_first_and_bit(addr1, addr2, offset);
> > @@ -427,7 +427,7 @@ unsigned long find_next_bit_wrap(const unsigned long *addr,
> >  {
> >  	unsigned long bit = find_next_bit(addr, size, offset);
> >  
> > -	if (bit < size)
> > +	if (bit < size || offset == 0)
> >  		return bit;
> >  
> >  	bit = find_first_bit(addr, offset);
> > -- 
> > 2.39.2
diff mbox series

Patch

diff --git a/include/linux/find.h b/include/linux/find.h
index 5e4f39ef2e72..241b6d028eda 100644
--- a/include/linux/find.h
+++ b/include/linux/find.h
@@ -405,7 +405,7 @@  unsigned long find_next_and_bit_wrap(const unsigned long *addr1,
 {
 	unsigned long bit = find_next_and_bit(addr1, addr2, size, offset);
 
-	if (bit < size)
+	if (bit < size || offset == 0)
 		return bit;
 
 	bit = find_first_and_bit(addr1, addr2, offset);
@@ -427,7 +427,7 @@  unsigned long find_next_bit_wrap(const unsigned long *addr,
 {
 	unsigned long bit = find_next_bit(addr, size, offset);
 
-	if (bit < size)
+	if (bit < size || offset == 0)
 		return bit;
 
 	bit = find_first_bit(addr, offset);