Messages in this thread | | | Date | Thu, 13 Mar 2014 12:34:32 +0000 | From | Zoltan Kiss <> | Subject | Re: [PATCH net-next v7 4/9] xen-netback: Introduce TX grant mapping |
| |
On 13/03/14 10:17, Ian Campbell wrote: > Pulling out this one comment for the attention on the core Xen/Linux > maintainers. > > On Thu, 2014-03-06 at 21:48 +0000, Zoltan Kiss wrote: > [...] >> @@ -343,8 +347,26 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, >> vif->pending_prod = MAX_PENDING_REQS; >> for (i = 0; i < MAX_PENDING_REQS; i++) >> vif->pending_ring[i] = i; >> - for (i = 0; i < MAX_PENDING_REQS; i++) >> - vif->mmap_pages[i] = NULL; >> + spin_lock_init(&vif->callback_lock); >> + spin_lock_init(&vif->response_lock); >> + /* If ballooning is disabled, this will consume real memory, so you >> + * better enable it. The long term solution would be to use just a >> + * bunch of valid page descriptors, without dependency on ballooning >> + */ > > I wonder if we ought to enforce this via Kconfig? i.e. making > CONFIG_XEN_BACKEND (or the individual backends) depend on BALLOON (or > select?) or by making CONFIG_XEN_BALLOON non-optional etc. I support this idea, but let's have other's views. > > IIRC David V was looking into a solution involving auto hotplugging a > new region to use for this case, but then I guess > CONFIG_XEN_BALLOON_MEMORY_HOTPLUG would equally need to be enabled. Yes, if that happens in the near future, we shouldn't be bothered by the above right now.
> >> + err = alloc_xenballooned_pages(MAX_PENDING_REQS, >> + vif->mmap_pages, >> + false); > [...] >
| |