On 20.11.18 09:45, Pankaj Gupta wrote: > > Hi David, > >> >> Mark inflated and never onlined pages PG_offline, to tell the world that >> the content is stale and should not be dumped. >> >> Cc: "K. Y. Srinivasan" <[email protected]> >> Cc: Haiyang Zhang <[email protected]> >> Cc: Stephen Hemminger <[email protected]> >> Cc: Kairui Song <[email protected]> >> Cc: Vitaly Kuznetsov <[email protected]> >> Cc: Andrew Morton <[email protected]> >> Cc: Matthew Wilcox <[email protected]> >> Cc: Michal Hocko <[email protected]> >> Cc: "Michael S. Tsirkin" <[email protected]> >> Signed-off-by: David Hildenbrand <[email protected]> >> --- >> drivers/hv/hv_balloon.c | 14 ++++++++++++-- >> 1 file changed, 12 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c >> index 211f3fe3a038..47719862e57f 100644 >> --- a/drivers/hv/hv_balloon.c >> +++ b/drivers/hv/hv_balloon.c >> @@ -681,8 +681,13 @@ static struct notifier_block hv_memory_nb = { >> /* Check if the particular page is backed and can be onlined and online it. >> */ >> static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg) >> { >> - if (!has_pfn_is_backed(has, page_to_pfn(pg))) >> + if (!has_pfn_is_backed(has, page_to_pfn(pg))) { >> + if (!PageOffline(pg)) >> + __SetPageOffline(pg); >> return; >> + } >> + if (PageOffline(pg)) >> + __ClearPageOffline(pg); >> >> /* This frame is currently backed; online the page. */ >> __online_page_set_limits(pg); >> @@ -1201,6 +1206,7 @@ static void free_balloon_pages(struct hv_dynmem_device >> *dm, >> >> for (i = 0; i < num_pages; i++) { >> pg = pfn_to_page(i + start_frame); >> + __ClearPageOffline(pg); > > Just thinking, do we need to care for clearing PageOffline flag before freeing > a balloon'd page?
Yes we have to otherwise the code will crash when trying to set PageBuddy. (only one page type at a time may be set right now, and it makes sense. A page that is offline cannot e.g. be a buddy page) So PageOffline is completely managed by the page owner. > > Thanks, > Pankaj -- Thanks, David / dhildenb _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
