Messages in this thread | | | Date | Tue, 16 Dec 2008 12:55:02 +0530 | From | Vaidyanathan Srinivasan <> | Subject | Re: [RFC PATCH v5 4/7] sched: bias task wakeups to preferred semi-idle packages |
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* Balbir Singh <balbir@linux.vnet.ibm.com> [2008-12-15 23:32:36]:
> >> > > Sure its racy, but so what? > >> > > > >> > > The worst I can see it that we exclude a dying task from this logic, > >> > > which isn't a problem at all, since its dying anyway. > >> > > >> > At which point I seriously doubt it'd still be on the rq anyway. > >> > > >> > >> I forgot to mention that, the check should be (p->mm && !(p->flags & PF_KTHREAD)) > > > > I can check for PF_KTHREAD for now. However, I should reduce the > > number of checks since this may slow down wake_idle for sched_mc=2. > > > > We can tolerate p->mm check on a dying process as Peter has suggested, > > hence we don't need to protect it. We are not going to access any > > contents of the mm struct. > > > > If PF_KTHREAD is only being used by AIO, then I feel we can drop the > > check since the threads will not have affinity and they can be moved > > to other cpus anyway. > > > > The main reason for skipping kthread is that they may be using per-cpu > > variables and sleep/preempted. I did not want the wake_idle() logic > > to move them around forcefully. This is not the general case and this > > situation should not happen. > > > > Second reason is to optimise on the affinity check since most of the > > kthreads have affinity and cannot be moved. > > > > This condition check needs optimisation after getting the framework > > functionally correct and useful. > > > Vaidy, you (or your mailer) seem to have dropped me off of the to/cc > list while replying and this seems to be the case for all replies.
Hi Balbir,
Thanks for pointing that out. I will review my mutt setup. This is strange... since a group-reply to this message puts you in the to list as expected, but not the ones that I sent earlier in reply to your messages. The header seems to be correct for others except for your message :(
--Vaidy
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