2021-12-21 01:15:03

by Yang Li

Subject: [PATCH -next] net/sched: use min() macro instead of doing it manually

Fix following coccicheck warnings:
./net/sched/cls_api.c:3333:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3389:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3427:17-18: WARNING opportunity for min()

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
net/sched/cls_api.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index c93699ddae36..a53c72e6d944 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -3333,7 +3333,7 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
- return ok_count < 0 ? ok_count : 0;
+ return min(ok_count, 0);
}
EXPORT_SYMBOL(tc_setup_cb_add);

@@ -3389,7 +3389,7 @@ int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
- return ok_count < 0 ? ok_count : 0;
+ return min(ok_count, 0);
}
EXPORT_SYMBOL(tc_setup_cb_replace);

@@ -3427,7 +3427,7 @@ int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
- return ok_count < 0 ? ok_count : 0;
+ return min(ok_count, 0);
}
EXPORT_SYMBOL(tc_setup_cb_destroy);

--
2.20.1.7.g153144c

2021-12-21 10:20:15

by patchwork-bot+netdevbpf

Subject: Re: [PATCH -next] net/sched: use min() macro instead of doing it manually

Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <[email protected]>:

On Tue, 21 Dec 2021 09:14:55 +0800 you wrote:
> Fix following coccicheck warnings:
> ./net/sched/cls_api.c:3333:17-18: WARNING opportunity for min()
> ./net/sched/cls_api.c:3389:17-18: WARNING opportunity for min()
> ./net/sched/cls_api.c:3427:17-18: WARNING opportunity for min()
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
>
> [...]

Here is the summary with links:
- [-next] net/sched: use min() macro instead of doing it manually
https://git.kernel.org/netdev/net-next/c/c48c94b0ab75

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

2021-12-21 10:47:51

by Joe Perches

Subject: Re: [PATCH -next] net/sched: use min() macro instead of doing it manually

On Tue, 2021-12-21 at 10:20 +0000, [email protected]
wrote:
> Hello:
>
> This patch was applied to netdev/net-next.git (master)
> by David S. Miller <[email protected]>:
>
> On Tue, 21 Dec 2021 09:14:55 +0800 you wrote:
> > Fix following coccicheck warnings:
> > ./net/sched/cls_api.c:3333:17-18: WARNING opportunity for min()
> > ./net/sched/cls_api.c:3389:17-18: WARNING opportunity for min()
> > ./net/sched/cls_api.c:3427:17-18: WARNING opportunity for min()
> >
> > Reported-by: Abaci Robot <[email protected]>
> > Signed-off-by: Yang Li <[email protected]>
> >
> > [...]
>
> Here is the summary with links:
> - [-next] net/sched: use min() macro instead of doing it manually
> https://git.kernel.org/netdev/net-next/c/c48c94b0ab75
>
> You are awesome, thank you!

The patch contained instances like:

---
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
[]
@@ -3333,7 +3333,7 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
up_read(&block->cb_lock);
if (take_rtnl)
rtnl_unlock();
- return ok_count < 0 ? ok_count : 0;
+ return min(ok_count, 0);
}
---

I think all of these min uses are somewhat obfuscating and not the
typically used kernel pattern.

If count is negative, it's an error return.

I believe the code would be clearer and more typical if written as:

if (ok_count < 0)
return ok_count;

return 0;
}

The compiler should produce the same object code.