> From: Vivek Goyal <vgoyal@xxxxxxxxxx> > Date: Fri, Nov 21, 2008 09:58:23AM -0500 > > On Fri, Nov 21, 2008 at 04:05:33AM +0100, Fabio Checconi wrote: > > > From: Vivek Goyal <vgoyal@xxxxxxxxxx> > > > Date: Thu, Nov 20, 2008 04:31:55PM -0500 > > > > > ... > > > Hi Fabio, > > > > > > I though will give bfq a try. I get following when I put my current shell > > > into a newly created cgroup and then try to do "ls". > > > > > > > The posted patch cannot work as it is, I'm sorry for that ugly bug. > > Do you still have problems with this one applied? > > > > --- > > diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c > > index efb03fc..ed8c597 100644 > > --- a/block/bfq-cgroup.c > > +++ b/block/bfq-cgroup.c > > @@ -168,7 +168,7 @@ static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup, > > > > spin_lock_irqsave(&bgrp->lock, flags); > > > > - rcu_assign_pointer(bfqg->bfqd, bfqd); > > + rcu_assign_pointer(leaf->bfqd, bfqd); > > hlist_add_head_rcu(&leaf->group_node, &bgrp->group_data); > > hlist_add_head(&leaf->bfqd_node, &bfqd->group_list); > > Thanks Fabio. This fix solves the issue for me. > Ok thank you. > I did a quick testing and I can see the differential service if I create > two cgroups of different priority. How do I map ioprio to shares? I > mean lets say one cgroup has ioprio 4 and other has got ioprio 7, then > what's the respective share(%) of each cgroup? > I thought I wrote it somewhere, but maybe I missed that; weights are mapped linearly, in decreasing order of priority: weight = 8 - ioprio [ the calculation is done in bfq_weight_t bfq_ioprio_to_weight() ] So, with ioprio 4 you have weight 4, and with ioprio 7 you have weight 1. The shares, as long as the two tasks/groups are active on the disk, are 4/5 and 1/5 respectively. This interface is really ugly, but it allows compatible uses of ioprios with the two schedulers. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
