what will happen when the jiffies overflow ?
hi all: As far as I known, the var jiffies in the kernel will overflow after 497days as the Hz defined 100. So what waill happen when the jiffies overflow? thanks
Hi, On Thu, Sep 20, 2012 at 7:09 AM, Fan Yang <lljyangfan@gmail.com> wrote:
hi all: As far as I known, the var jiffies in the kernel will overflow after 497days as the Hz defined 100. So what waill happen when the jiffies overflow?
It will start back at zero. Everything should continue to work as before. In fact, jiffies are initialized to -300 seconds, so that it will overflow 5 minutes after startup, just to verify that everything works properly. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com
Btw, jiffies is now stored as a 64 bit variable internally in the kernel (not 32 bit), although to maintain compatibility with the older code, it can be still 'treated' as a 32-bit variable. In reality, overflow would take a lot more time than 497 days, but if you read only the first 32 bits, then you are right about the 497 day thing. ~Gaurav On Thu, Sep 20, 2012 at 8:30 PM, Dave Hylands <dhylands@gmail.com> wrote:
Hi,
On Thu, Sep 20, 2012 at 7:09 AM, Fan Yang <lljyangfan@gmail.com> wrote:
hi all: As far as I known, the var jiffies in the kernel will overflow after 497days as the Hz defined 100. So what waill happen when the jiffies overflow?
It will start back at zero.
Everything should continue to work as before.
In fact, jiffies are initialized to -300 seconds, so that it will overflow 5 minutes after startup, just to verify that everything works properly.
-- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com
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-- Gaurav Jain Associate Software Engineer VxVM Escalations Team, SAMG Symantec Software India Pvt. Ltd.
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Gaurav Jain