Messages in this thread Patch in this message | | | Subject | Re: [PATCH net-next v7 4/9] xen-netback: Introduce TX grant mapping | From | Ian Campbell <> | Date | Thu, 13 Mar 2014 10:17:54 +0000 |
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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.
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.
> + err = alloc_xenballooned_pages(MAX_PENDING_REQS, > + vif->mmap_pages, > + false); [...]
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