| Message ID | 20220210224933.379149-48-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Thu, Feb 10, 2022 at 02:49:31PM -0800, Yury Norov wrote: > Page allocator uses num_node_state() to compare number of nodes with a > given number. The underlying code calls bitmap_weight(), and we can do > it more efficiently with num_node_state_eq because conditional nodes_weight > may stop traversing the nodemask earlier, as soon as condition is (or is > not) met. > > Signed-off-by: Yury Norov <yury.norov@gmail.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> > --- > include/linux/nodemask.h | 5 +++++ > mm/page_alloc.c | 2 +- > 2 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h > index 197598e075e9..c5014dbf3cce 100644 > --- a/include/linux/nodemask.h > +++ b/include/linux/nodemask.h > @@ -466,6 +466,11 @@ static inline int num_node_state(enum node_states state) > return nodes_weight(node_states[state]); > } > > +static inline int num_node_state_eq(enum node_states state, int num) > +{ > + return nodes_weight_eq(node_states[state], num); > +} > + > #define for_each_node_state(__node, __state) \ > for_each_node_mask((__node), node_states[__state]) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cface1d38093..897e64b66ca4 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8434,7 +8434,7 @@ void __init page_alloc_init(void) > int ret; > > #ifdef CONFIG_NUMA > - if (num_node_state(N_MEMORY) == 1) > + if (num_node_state_eq(N_MEMORY, 1)) > hashdist = 0; > #endif > > -- > 2.32.0 > >
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h index 197598e075e9..c5014dbf3cce 100644 --- a/include/linux/nodemask.h +++ b/include/linux/nodemask.h @@ -466,6 +466,11 @@ static inline int num_node_state(enum node_states state) return nodes_weight(node_states[state]); } +static inline int num_node_state_eq(enum node_states state, int num) +{ + return nodes_weight_eq(node_states[state], num); +} + #define for_each_node_state(__node, __state) \ for_each_node_mask((__node), node_states[__state]) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cface1d38093..897e64b66ca4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8434,7 +8434,7 @@ void __init page_alloc_init(void) int ret; #ifdef CONFIG_NUMA - if (num_node_state(N_MEMORY) == 1) + if (num_node_state_eq(N_MEMORY, 1)) hashdist = 0; #endif
Page allocator uses num_node_state() to compare number of nodes with a given number. The underlying code calls bitmap_weight(), and we can do it more efficiently with num_node_state_eq because conditional nodes_weight may stop traversing the nodemask earlier, as soon as condition is (or is not) met. Signed-off-by: Yury Norov <yury.norov@gmail.com> --- include/linux/nodemask.h | 5 +++++ mm/page_alloc.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)