Messages in this thread | | | Subject | Re: [PATCH] dn_route: use time_is_before_jiffies(a) to replace "jiffies - a > 0" | From | Yu Zhe <> | Date | Fri, 29 Jul 2022 13:49:09 +0800 |
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在 2022年07月28日 21:11, Paolo Abeni 写道:
> On Wed, 2022-07-27 at 10:46 +0800, Yu Zhe wrote: >> time_is_before_jiffies deals with timer wrapping correctly. >> >> Signed-off-by: Yu Zhe <yuzhe@nfschina.com> >> --- >> net/decnet/dn_route.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c >> index 552a53f1d5d0..0a4bed0bc2e3 100644 >> --- a/net/decnet/dn_route.c >> +++ b/net/decnet/dn_route.c >> @@ -201,7 +201,7 @@ static void dn_dst_check_expire(struct timer_list *unused) >> } >> spin_unlock(&dn_rt_hash_table[i].lock); >> >> - if ((jiffies - now) > 0) >> + if (time_is_before_jiffies(now)) > Uhmm... it looks like the wrap-around condition can happen only in > theory: 'now' is initialized just before entering this loop, and we > will break as soon as jiffies increment. The wrap-around could happen > only if a single iteration of the loop takes more than LONG_MAX > jiffies. > > If that happens, we have a completely different kind of much more > serious problem, I think ;) > > So this change is mostly for core readability's sake. I personally find > more readable: > > if (jiffies != now)
I agree and I will send a v2 patch later.
> > Cheers, > > Paolo > > p.s. given the above I guess this is for the net-next tree, right? > yes
>
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