On Tue, 27 Aug 2013 20:11:41 +0000 "Nicholas A. Bellinger" <n...@linux-iscsi.org> wrote:
> Percpu frontend for allocating ids. With percpu allocation (that works), > it's impossible to guarantee it will always be possible to allocate all > nr_tags - typically, some will be stuck on a remote percpu freelist > where the current job can't get to them. > > We do guarantee that it will always be possible to allocate at least > (nr_tags / 2) tags - this is done by keeping track of which and how many > cpus have tags on their percpu freelists. On allocation failure if > enough cpus have tags that there could potentially be (nr_tags / 2) tags > stuck on remote percpu freelists, we then pick a remote cpu at random to > steal from. > > Note that there's no cpu hotplug notifier - we don't care, because > steal_tags() will eventually get the down cpu's tags. We _could_ satisfy > more allocations if we had a notifier - but we'll still meet our > guarantees and it's absolutely not a correctness issue, so I don't think > it's worth the extra code. Except for one silly trivial thing, all of my August 20 review comments were ignored. You didn't even bother replying to the email. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
