Re: [PATCH] net: convert gro_count to bitmask

[Stefano Brivio <sbrivio@redhat.com>]

On Thu, 12 Jul 2018 02:31:10 +0000
"Li,Rongqing" <lirongqing@baidu.com> wrote:

> > -----邮件原件-----
> > 发件人: Stefano Brivio [mailto:sbrivio@redhat.com]
> > 发送时间: 2018年7月11日 18:52
> > 收件人: Li,Rongqing <lirongqing@baidu.com>
> > 抄送: netdev@vger.kernel.org; Eric Dumazet <edumazet@google.com>
> > 主题: Re: [PATCH] net: convert gro_count to bitmask
> > 
> > On Wed, 11 Jul 2018 17:15:53 +0800
> > Li RongQing <lirongqing@baidu.com> wrote:
> >   
> > > @@ -5380,6 +5382,12 @@ static enum gro_result dev_gro_receive(struct  
> > napi_struct *napi, struct sk_buff  
> > >  	if (grow > 0)
> > >  		gro_pull_from_frag0(skb, grow);
> > >  ok:
> > > +	if (napi->gro_hash[hash].count)
> > > +		if (!test_bit(hash, &napi->gro_bitmask))
> > > +			set_bit(hash, &napi->gro_bitmask);
> > > +	else if (test_bit(hash, &napi->gro_bitmask))
> > > +		clear_bit(hash, &napi->gro_bitmask);  
> > 
> > This might not do what you want.
> > 
> > --  
> 
> could you show detail ?

$ cat if1.c; gcc -o if1 if1.c
#include <stdio.h>

int main()
{
	if (1)
		if (0)
			;
	else if (2)
		printf("whoops\n");

	return 0;
}
$ ./if1
whoops

$ cat if2.c; gcc -o if2 if2.c
#include <stdio.h>

int main()
{
	if (1) {
		if (0)
			;
	} else if (2) {
		printf("whoops\n");
	}

	return 0;
}
$ ./if2

-- 
Stefano