Re: [PATCH v2 2/7] xen/page_alloc: Remove `claim` from domain_set_outstanding_pages()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 16.08.2025 13:19, Bernhard Kaindl wrote:
> With a single global count for the claims it is easy to substract
> domain_tot_pages() from the claim so the number given in the hypercall
> is the real reservation of the domain. This is the current behaviour.
> 
> However, a later patch introduces node-specific claims and those interact
> very poorly with such a scheme. Since accounting domain_tot_pages() in
> one case but not the other seems strictly worse than not accounting them
> at all (which is at least consistent), this patch stops substracting
> tot_pages from the claim and instead checks that claimed memory +
> allocated memory don't exceed max_mem.
> 
> Arguably it's also clearer for the caller to align the amount of claimed
> memory with that of the requested claim. xl/libxenguest code never updated
> an existing claim: It stakes a claim, allocates all domain memory, cancels
> a possible leftover claim, finishes building the domain and unpauses it.
> 
> Signed-off-by: Bernhard Kaindl <bernhard.kaindl@xxxxxxxxx>
> Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@xxxxxxx>

Is this order (and the lack of From:) correct? A patch of the same title was
submitted by Alejandro at some point. Additionally the cover letter lists
this one patch as the sole Alejandro-only one. I'm also uncertain if you may
freely alter the original S-o-b, which was still having his @cloud.com email
address afaict.

> ---
>  xen/common/page_alloc.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)

>From eyeballing both patches nothing has changed. That would support the
tagging as Alejandro-only in the cover letter, but it also means review
comments weren't addressed. Such non-addressing would, however, require a
verbal reply to those review comments, which I can't find any record of.
Instead in a reply to Roger's comments Alejandro indicated that there
indeed was an oversight on his part. My separate comment wasn't replied to
at all.

Jan