| Message ID | 20200724124241.48208-2-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/balloon: fixes for memory hotplug | expand |
On 24.07.20 14:42, Roger Pau Monne wrote: > target_unpopulated is incremented with nr_pages at the start of the > function, but the call to free_xenballooned_pages will only subtract > pgno number of pages, and thus the rest need to be subtracted before > returning or else accounting will be skewed. > > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Juergen
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 77c57568e5d7..3cb10ed32557 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -630,6 +630,12 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) out_undo: mutex_unlock(&balloon_mutex); free_xenballooned_pages(pgno, pages); + /* + * NB: free_xenballooned_pages will only subtract pgno pages, but since + * target_unpopulated is incremented with nr_pages at the start we need + * to remove the remaining ones also, or accounting will be screwed. + */ + balloon_stats.target_unpopulated -= nr_pages - pgno; return ret; } EXPORT_SYMBOL(alloc_xenballooned_pages);
target_unpopulated is incremented with nr_pages at the start of the function, but the call to free_xenballooned_pages will only subtract pgno number of pages, and thus the rest need to be subtracted before returning or else accounting will be skewed. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: stable@vger.kernel.org --- Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: xen-devel@lists.xenproject.org --- drivers/xen/balloon.c | 6 ++++++ 1 file changed, 6 insertions(+)