All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] maple_tree: Do not inline write slow path
@ 2022-07-21  0:53 Liam Howlett
  2022-07-21  8:26 ` David Laight
  0 siblings, 1 reply; 3+ messages in thread
From: Liam Howlett @ 2022-07-21  0:53 UTC (permalink / raw)
  To: maple-tree, linux-mm, linux-kernel, Andrew Morton, Hugh Dickins; +Cc: Yu Zhao

Having the slow path inlined causes too much stack usage.  Create new
function mas_wr_bnode() to write a big node into the tree

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 95d8659c5a99..4c383c780162 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4297,12 +4297,27 @@ static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
 	return false;
 }
 
+/*
+ * mas_wr_bnode() - Slow path for a modification.
+ * @wr_mas: The write maple state
+ *
+ * This is where split, rebalance end up.
+ */
+static void mas_wr_bnode(struct ma_wr_state *wr_mas)
+{
+	struct maple_big_node b_node;
+
+	trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
+	memset(&b_node, 0, sizeof(struct maple_big_node));
+	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
+	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
+}
+
 static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
 {
 	unsigned char node_slots;
 	unsigned char node_size;
 	struct ma_state *mas = wr_mas->mas;
-	struct maple_big_node b_node;
 
 	/* Direct replacement */
 	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
@@ -4338,10 +4353,7 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
 		return;
 
 slow_path:
-	memset(&b_node, 0, sizeof(struct maple_big_node));
-	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
-	trace_ma_write(__func__, mas, 0, wr_mas->entry);
-	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
+	mas_wr_bnode(wr_mas);
 }
 
 /*
-- 
2.35.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* RE: [PATCH] maple_tree: Do not inline write slow path
  2022-07-21  0:53 [PATCH] maple_tree: Do not inline write slow path Liam Howlett
@ 2022-07-21  8:26 ` David Laight
  2022-07-21 19:30   ` Liam Howlett
  0 siblings, 1 reply; 3+ messages in thread
From: David Laight @ 2022-07-21  8:26 UTC (permalink / raw)
  To: 'Liam Howlett',
	maple-tree, linux-mm, linux-kernel, Andrew Morton, Hugh Dickins
  Cc: Yu Zhao

From: Liam Howlett
> Sent: 21 July 2022 01:53
> 
> Having the slow path inlined causes too much stack usage.  Create new
> function mas_wr_bnode() to write a big node into the tree

Unless you mark the function 'noinline' the compiler is
likely to inline it anyway.

	David

> 
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
>  lib/maple_tree.c | 22 +++++++++++++++++-----
>  1 file changed, 17 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 95d8659c5a99..4c383c780162 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4297,12 +4297,27 @@ static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
>  	return false;
>  }
> 
> +/*
> + * mas_wr_bnode() - Slow path for a modification.
> + * @wr_mas: The write maple state
> + *
> + * This is where split, rebalance end up.
> + */
> +static void mas_wr_bnode(struct ma_wr_state *wr_mas)
> +{
> +	struct maple_big_node b_node;
> +
> +	trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
> +	memset(&b_node, 0, sizeof(struct maple_big_node));
> +	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
> +	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
> +}
> +
>  static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
>  {
>  	unsigned char node_slots;
>  	unsigned char node_size;
>  	struct ma_state *mas = wr_mas->mas;
> -	struct maple_big_node b_node;
> 
>  	/* Direct replacement */
>  	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
> @@ -4338,10 +4353,7 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
>  		return;
> 
>  slow_path:
> -	memset(&b_node, 0, sizeof(struct maple_big_node));
> -	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
> -	trace_ma_write(__func__, mas, 0, wr_mas->entry);
> -	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
> +	mas_wr_bnode(wr_mas);
>  }
> 
>  /*
> --
> 2.35.1

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH] maple_tree: Do not inline write slow path
  2022-07-21  8:26 ` David Laight
@ 2022-07-21 19:30   ` Liam Howlett
  0 siblings, 0 replies; 3+ messages in thread
From: Liam Howlett @ 2022-07-21 19:30 UTC (permalink / raw)
  To: David Laight
  Cc: maple-tree, linux-mm, linux-kernel, Andrew Morton, Hugh Dickins, Yu Zhao

* David Laight <David.Laight@ACULAB.COM> [220721 04:26]:
> From: Liam Howlett
> > Sent: 21 July 2022 01:53
> > 
> > Having the slow path inlined causes too much stack usage.  Create new
> > function mas_wr_bnode() to write a big node into the tree
> 
> Unless you mark the function 'noinline' the compiler is
> likely to inline it anyway.
> 
> 	David

Thanks for looking at this.

On my testing, removing the inline allowed the compiler to stop
complaining about the stack frame size.  I don't mind if it is inlined,
but I don't want to force it to be inlined.  I'd like to let the
compiler decide if it does the right thing.

Thanks,
Liam

> 
> > 
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> > ---
> >  lib/maple_tree.c | 22 +++++++++++++++++-----
> >  1 file changed, 17 insertions(+), 5 deletions(-)
> > 
> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > index 95d8659c5a99..4c383c780162 100644
> > --- a/lib/maple_tree.c
> > +++ b/lib/maple_tree.c
> > @@ -4297,12 +4297,27 @@ static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
> >  	return false;
> >  }
> > 
> > +/*
> > + * mas_wr_bnode() - Slow path for a modification.
> > + * @wr_mas: The write maple state
> > + *
> > + * This is where split, rebalance end up.
> > + */
> > +static void mas_wr_bnode(struct ma_wr_state *wr_mas)
> > +{
> > +	struct maple_big_node b_node;
> > +
> > +	trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
> > +	memset(&b_node, 0, sizeof(struct maple_big_node));
> > +	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
> > +	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
> > +}
> > +
> >  static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
> >  {
> >  	unsigned char node_slots;
> >  	unsigned char node_size;
> >  	struct ma_state *mas = wr_mas->mas;
> > -	struct maple_big_node b_node;
> > 
> >  	/* Direct replacement */
> >  	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
> > @@ -4338,10 +4353,7 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
> >  		return;
> > 
> >  slow_path:
> > -	memset(&b_node, 0, sizeof(struct maple_big_node));
> > -	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
> > -	trace_ma_write(__func__, mas, 0, wr_mas->entry);
> > -	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
> > +	mas_wr_bnode(wr_mas);
> >  }
> > 
> >  /*
> > --
> > 2.35.1
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-07-21 19:30 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-21  0:53 [PATCH] maple_tree: Do not inline write slow path Liam Howlett
2022-07-21  8:26 ` David Laight
2022-07-21 19:30   ` Liam Howlett

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.