On Fri, Jul 31, 2009 at 10:43 PM, Chetan Nanda<chetanna...@gmail.com> wrote: > > > On Fri, Jul 31, 2009 at 12:33 PM, er krishna <erkris...@gmail.com> wrote: >> >> >> On Fri, Jul 31, 2009 at 11:21 AM, Vivek Subbarao <viv...@chelsio.com> >> wrote: >>> >>> >weather the second process has its priority must be higher than the >>> > running one ? >>> >>> Yes. Only a process of higher or same priority can pre-empt a process of >>> lower priority. >>> >>> >>> >>> If pre-empt_count is +ve means that i can be pre-empted then you are >>> right. >> >> If a lower process has taken a lock & its preempt_count value is +ve , can >> it be preempted by higher priority process ? > > positive value of preempt_count means that kernel preemption is disabled, in > that case even high priority process will not be able to preempt low > priority process, people please CMIIW
This is correct. A positive value disables preemption. >> >> >> >>> >>> >>> >>> From: kernelnewbies-bou...@nl.linux.org >>> [mailto:kernelnewbies-bou...@nl.linux.org] On Behalf Of er krishna >>> Sent: 30 July 2009 14:32 >>> To: kernelnewbies@nl.linux.org >>> Subject: preemption >>> >>> >>> >>> Dear All, >>> >>> I have some confusion about preemption. Can anybody please clear my query >>> : >>> >>> 1) If there are two process running in kernel space & one of them has a >>> lock & its preempt_count value is +ve , can the other process preempt it ? >>> If it preempt the first process ( which is in running state with a lock ) , >>> then how ( weather the second process has its priority must be higher than >>> the running one ? )? >>> >>> Thanks & Best Regards, >>> Krishna > > Thanks, > Chetan Nanda > Regards, Sandeep. “To learn is to change. Education is a process that changes the learner.” -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
