diff mbox series

[net-next,v9,1/3] net: extract napi poll functionality to __napi_poll()

Message ID 20210129181812.256216-2-weiwan@google.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series implement kthread based napi poll | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 6 maintainers not CCed: andriin@fb.com daniel@iogearbox.net bjorn@kernel.org ap420073@gmail.com ast@kernel.org xiyou.wangcong@gmail.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 10 this patch: 10
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 70 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 10 this patch: 10
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Wei Wang Jan. 29, 2021, 6:18 p.m. UTC 
From: Felix Fietkau <nbd@nbd.name> 

This commit introduces a new function __napi_poll() which does the main
logic of the existing napi_poll() function, and will be called by other
functions in later commits.
This idea and implementation is done by Felix Fietkau <nbd@nbd.name> and
is proposed as part of the patch to move napi work to work_queue
context.
This commit by itself is a code restructure.

Signed-off-by: Felix Fietkau <nbd@nbd.name> 
Signed-off-by: Wei Wang <weiwan@google.com>
---
 net/core/dev.c | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

Comments

Alexander Duyck Feb. 3, 2021, 5 p.m. UTC | #1 
On Fri, Jan 29, 2021 at 10:20 AM Wei Wang <weiwan@google.com> wrote:
>
> From: Felix Fietkau <nbd@nbd.name>
>
> This commit introduces a new function __napi_poll() which does the main
> logic of the existing napi_poll() function, and will be called by other
> functions in later commits.
> This idea and implementation is done by Felix Fietkau <nbd@nbd.name> and
> is proposed as part of the patch to move napi work to work_queue
> context.
> This commit by itself is a code restructure.
>
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> Signed-off-by: Wei Wang <weiwan@google.com>
> ---
>  net/core/dev.c | 35 +++++++++++++++++++++++++----------
>  1 file changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 0332f2e8f7da..7d23bff03864 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -6768,15 +6768,10 @@ void __netif_napi_del(struct napi_struct *napi)
>  }
>  EXPORT_SYMBOL(__netif_napi_del);
>
> -static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> +static int __napi_poll(struct napi_struct *n, bool *repoll)
>  {
> -       void *have;
>         int work, weight;
>
> -       list_del_init(&n->poll_list);
> -
> -       have = netpoll_poll_lock(n);
> -
>         weight = n->weight;
>
>         /* This NAPI_STATE_SCHED test is for avoiding a race
> @@ -6796,7 +6791,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
>                             n->poll, work, weight);
>
>         if (likely(work < weight))
> -               goto out_unlock;
> +               return work;
>
>         /* Drivers must not modify the NAPI state if they
>          * consume the entire weight.  In such cases this code
> @@ -6805,7 +6800,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
>          */
>         if (unlikely(napi_disable_pending(n))) {
>                 napi_complete(n);
> -               goto out_unlock;
> +               return work;
>         }
>
>         /* The NAPI context has more processing work, but busy-polling
> @@ -6818,7 +6813,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
>                          */
>                         napi_schedule(n);
>                 }
> -               goto out_unlock;
> +               return work;
>         }
>
>         if (n->gro_bitmask) {
> @@ -6836,9 +6831,29 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
>         if (unlikely(!list_empty(&n->poll_list))) {
>                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
>                              n->dev ? n->dev->name : "backlog");
> -               goto out_unlock;
> +               return work;
>         }
>
> +       *repoll = true;
> +
> +       return work;
> +}
> +
> +static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> +{
> +       bool do_repoll = false;
> +       void *have;
> +       int work;
> +
> +       list_del_init(&n->poll_list);
> +
> +       have = netpoll_poll_lock(n);
> +
> +       work = __napi_poll(n, &do_repoll);
> +
> +       if (!do_repoll)
> +               goto out_unlock;
> +
>         list_add_tail(&n->poll_list, repoll);
>
>  out_unlock:

Instead of using the out_unlock label why don't you only do the
list_add_tail if do_repoll is true? It will allow you to drop a few
lines of noise. Otherwise this looks good to me.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Wei Wang Feb. 3, 2021, 5:57 p.m. UTC | #2 
On Wed, Feb 3, 2021 at 9:00 AM Alexander Duyck
<alexander.duyck@gmail.com> wrote:
>
> On Fri, Jan 29, 2021 at 10:20 AM Wei Wang <weiwan@google.com> wrote:
> >
> > From: Felix Fietkau <nbd@nbd.name>
> >
> > This commit introduces a new function __napi_poll() which does the main
> > logic of the existing napi_poll() function, and will be called by other
> > functions in later commits.
> > This idea and implementation is done by Felix Fietkau <nbd@nbd.name> and
> > is proposed as part of the patch to move napi work to work_queue
> > context.
> > This commit by itself is a code restructure.
> >
> > Signed-off-by: Felix Fietkau <nbd@nbd.name>
> > Signed-off-by: Wei Wang <weiwan@google.com>
> > ---
> >  net/core/dev.c | 35 +++++++++++++++++++++++++----------
> >  1 file changed, 25 insertions(+), 10 deletions(-)
> >
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index 0332f2e8f7da..7d23bff03864 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -6768,15 +6768,10 @@ void __netif_napi_del(struct napi_struct *napi)
> >  }
> >  EXPORT_SYMBOL(__netif_napi_del);
> >
> > -static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> > +static int __napi_poll(struct napi_struct *n, bool *repoll)
> >  {
> > -       void *have;
> >         int work, weight;
> >
> > -       list_del_init(&n->poll_list);
> > -
> > -       have = netpoll_poll_lock(n);
> > -
> >         weight = n->weight;
> >
> >         /* This NAPI_STATE_SCHED test is for avoiding a race
> > @@ -6796,7 +6791,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> >                             n->poll, work, weight);
> >
> >         if (likely(work < weight))
> > -               goto out_unlock;
> > +               return work;
> >
> >         /* Drivers must not modify the NAPI state if they
> >          * consume the entire weight.  In such cases this code
> > @@ -6805,7 +6800,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> >          */
> >         if (unlikely(napi_disable_pending(n))) {
> >                 napi_complete(n);
> > -               goto out_unlock;
> > +               return work;
> >         }
> >
> >         /* The NAPI context has more processing work, but busy-polling
> > @@ -6818,7 +6813,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> >                          */
> >                         napi_schedule(n);
> >                 }
> > -               goto out_unlock;
> > +               return work;
> >         }
> >
> >         if (n->gro_bitmask) {
> > @@ -6836,9 +6831,29 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> >         if (unlikely(!list_empty(&n->poll_list))) {
> >                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
> >                              n->dev ? n->dev->name : "backlog");
> > -               goto out_unlock;
> > +               return work;
> >         }
> >
> > +       *repoll = true;
> > +
> > +       return work;
> > +}
> > +
> > +static int napi_poll(struct napi_struct *n, struct list_head *repoll)
> > +{
> > +       bool do_repoll = false;
> > +       void *have;
> > +       int work;
> > +
> > +       list_del_init(&n->poll_list);
> > +
> > +       have = netpoll_poll_lock(n);
> > +
> > +       work = __napi_poll(n, &do_repoll);
> > +
> > +       if (!do_repoll)
> > +               goto out_unlock;
> > +
> >         list_add_tail(&n->poll_list, repoll);
> >
> >  out_unlock:
>
> Instead of using the out_unlock label why don't you only do the
> list_add_tail if do_repoll is true? It will allow you to drop a few
> lines of noise. Otherwise this looks good to me.
>
Ack.

> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Thanks for the review.
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 0332f2e8f7da..7d23bff03864 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6768,15 +6768,10 @@  void __netif_napi_del(struct napi_struct *napi)
 }
 EXPORT_SYMBOL(__netif_napi_del);
 
-static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+static int __napi_poll(struct napi_struct *n, bool *repoll)
 {
-	void *have;
 	int work, weight;
 
-	list_del_init(&n->poll_list);
-
-	have = netpoll_poll_lock(n);
-
 	weight = n->weight;
 
 	/* This NAPI_STATE_SCHED test is for avoiding a race
@@ -6796,7 +6791,7 @@  static int napi_poll(struct napi_struct *n, struct list_head *repoll)
 			    n->poll, work, weight);
 
 	if (likely(work < weight))
-		goto out_unlock;
+		return work;
 
 	/* Drivers must not modify the NAPI state if they
 	 * consume the entire weight.  In such cases this code
@@ -6805,7 +6800,7 @@  static int napi_poll(struct napi_struct *n, struct list_head *repoll)
 	 */
 	if (unlikely(napi_disable_pending(n))) {
 		napi_complete(n);
-		goto out_unlock;
+		return work;
 	}
 
 	/* The NAPI context has more processing work, but busy-polling
@@ -6818,7 +6813,7 @@  static int napi_poll(struct napi_struct *n, struct list_head *repoll)
 			 */
 			napi_schedule(n);
 		}
-		goto out_unlock;
+		return work;
 	}
 
 	if (n->gro_bitmask) {
@@ -6836,9 +6831,29 @@  static int napi_poll(struct napi_struct *n, struct list_head *repoll)
 	if (unlikely(!list_empty(&n->poll_list))) {
 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
 			     n->dev ? n->dev->name : "backlog");
-		goto out_unlock;
+		return work;
 	}
 
+	*repoll = true;
+
+	return work;
+}
+
+static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+{
+	bool do_repoll = false;
+	void *have;
+	int work;
+
+	list_del_init(&n->poll_list);
+
+	have = netpoll_poll_lock(n);
+
+	work = __napi_poll(n, &do_repoll);
+
+	if (!do_repoll)
+		goto out_unlock;
+
 	list_add_tail(&n->poll_list, repoll);
 
 out_unlock: