On 08.01.2026 18:55, Roger Pau Monne wrote:
> Such parameter allow requesting to scrub memory only from the specified
> node. If there's no memory to scrub from the requested node the function
> returns false. If the node is already being scrubbed from a different CPU
> the function returns true so the caller can differentiate whether there's
> still pending work to do.
I'm really trying to understand both patches together, and peeking ahead I
don't understand the above, which looks to describe ...
> --- a/xen/common/page_alloc.c
> +++ b/xen/common/page_alloc.c
> @@ -1339,16 +1339,27 @@ static void cf_check scrub_continue(void *data)
> }
> }
>
> -bool scrub_free_pages(void)
> +bool scrub_free_pages(nodeid_t node)
> {
> struct page_info *pg;
> unsigned int zone;
> unsigned int cpu = smp_processor_id();
> bool preempt = false;
> - nodeid_t node;
> unsigned int cnt = 0;
>
> - node = node_to_scrub(true);
> + if ( node != NUMA_NO_NODE )
> + {
> + if ( !node_need_scrub[node] )
> + /* Nothing to scrub. */
> + return false;
> +
> + if ( node_test_and_set(node, node_scrubbing) )
> + /* Another CPU is scrubbing it. */
> + return true;
... these two return-s. My problem being that patch 2 doesn't use the
return value (while existing callers don't take this path). Is this then
"just in case" for now (and making the meaning of the return values
somewhat inconsistent for the function as a whole)?
Jan
