* Re: sched: about vruntime overflow [not found] <47CEA9C0E570484FBF22EF0D7EBCE5B534B17A98@szxema505-mbs.china.huawei.com> @ 2015-07-07 9:10 ` Peter Zijlstra 2015-07-07 9:18 ` Gaohaifeng (A) 0 siblings, 1 reply; 2+ messages in thread From: Peter Zijlstra @ 2015-07-07 9:10 UTC (permalink / raw) To: Gaohaifeng (A); +Cc: linux-kernel, stephan.baerwolf, Huangjian (J) On Tue, Jul 07, 2015 at 08:05:50AM +0000, Gaohaifeng (A) wrote: > int main() > { > unsigned char a,b; > a=251; > b=254; > b +=5; // b will overflow > printf("a=%u \n",a); > printf("b=%u \n",b); > printf("(a-b<0)=%d\n",(a-b)<0); If you look at entity_before() you'll notice that the correct statement would be: printf("(a-b<0)=%d\n",(signed char)(a-b)<0); > printf("(a-b<0)=%d\n",((unsigned char)(a-250)-(unsigned char)(b-250)<0)); > return 0; > } ^ permalink raw reply [flat|nested] 2+ messages in thread
* RE: sched: about vruntime overflow 2015-07-07 9:10 ` sched: about vruntime overflow Peter Zijlstra @ 2015-07-07 9:18 ` Gaohaifeng (A) 0 siblings, 0 replies; 2+ messages in thread From: Gaohaifeng (A) @ 2015-07-07 9:18 UTC (permalink / raw) To: Peter Zijlstra; +Cc: linux-kernel, stephan.baerwolf, Huangjian (J) Much Thanks! On Tue, Jul 07, 2015 at 08:05:50AM +0000, Gaohaifeng (A) wrote: > int main() > { > unsigned char a,b; > a=251; > b=254; > b +=5; // b will overflow > printf("a=%u \n",a); > printf("b=%u \n",b); > printf("(a-b<0)=%d\n",(a-b)<0); If you look at entity_before() you'll notice that the correct statement would be: printf("(a-b<0)=%d\n",(signed char)(a-b)<0); > printf("(a-b<0)=%d\n",((unsigned char)(a-250)-(unsigned char)(b-250)<0)); > return 0; > } ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-07-07 9:19 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <47CEA9C0E570484FBF22EF0D7EBCE5B534B17A98@szxema505-mbs.china.huawei.com>
2015-07-07 9:10 ` sched: about vruntime overflow Peter Zijlstra
2015-07-07 9:18 ` Gaohaifeng (A)
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®