* do we still need the jiffies wraparound functions ?
@ 2005-12-27 3:32 jeff shia
2005-12-27 4:02 ` Tim Schmielau
2005-12-27 4:04 ` Dave Jones
0 siblings, 2 replies; 3+ messages in thread
From: jeff shia @ 2005-12-27 3:32 UTC (permalink / raw)
To: linux-kernel
Hello,
Under the kernel 2.6.x,the jiffies is defined as u64.We cannot count
on it to overflow.
Do we still need the functions to solve this problem?
Thank you.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: do we still need the jiffies wraparound functions ?
2005-12-27 3:32 do we still need the jiffies wraparound functions ? jeff shia
@ 2005-12-27 4:02 ` Tim Schmielau
2005-12-27 4:04 ` Dave Jones
1 sibling, 0 replies; 3+ messages in thread
From: Tim Schmielau @ 2005-12-27 4:02 UTC (permalink / raw)
To: jeff shia; +Cc: linux-kernel
On Tue, 27 Dec 2005, jeff shia wrote:
> Under the kernel 2.6.x,the jiffies is defined as u64.We cannot count
> on it to overflow.
Actually, no. jiffies is still defined as unsigned long, which reduces
overhead where 64 bit jiffies are not needed. Only jiffies_64 is an u64.
> Do we still need the functions to solve this problem?
Yes.
Tim
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: do we still need the jiffies wraparound functions ?
2005-12-27 3:32 do we still need the jiffies wraparound functions ? jeff shia
2005-12-27 4:02 ` Tim Schmielau
@ 2005-12-27 4:04 ` Dave Jones
1 sibling, 0 replies; 3+ messages in thread
From: Dave Jones @ 2005-12-27 4:04 UTC (permalink / raw)
To: jeff shia; +Cc: linux-kernel
On Tue, Dec 27, 2005 at 11:32:41AM +0800, jeff shia wrote:
> Hello,
>
> Under the kernel 2.6.x,the jiffies is defined as u64.We cannot count
> on it to overflow.
You can guarantee it will overflow within a few minutes of booting.
This is done deliberatly to catch jiffy-wrap bugs.
> Do we still need the functions to solve this problem?
yes.
Dave
^ permalink raw reply [flat|nested] 3+ messages in thread
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2005-12-27 3:32 do we still need the jiffies wraparound functions ? jeff shia
2005-12-27 4:02 ` Tim Schmielau
2005-12-27 4:04 ` Dave Jones
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