On 04/24/2018 10:42 AM, Daniel P. Berrangé wrote: > On Mon, Apr 23, 2018 at 05:44:38PM +0200, Michal Privoznik wrote: >> https://bugzilla.redhat.com/show_bug.cgi?id=1569678 >> >> On some large systems (with ~400GB of RAM) it is possible for >> unsigned int to overflow in which case we report invalid number >> of 4K pages pool size. Switch to unsigned long long. > > It isn't very obvious from the code diff what the actual problem > is, but it is mentioned in the bug that we hit overflow in > virNumaGetPages when doing: > > huge_page_sum += 1024 * page_size * page_avail; > > because although 'huge_page_sum' is an unsigned long long, the > page_size and page_avail are both unsigned int, so the promotion > to unsigned long long doesn't happen until the sum has been > calculated, by which time we've already overflowed. Can you > mention that we're specifically solving this huge_page_sum > overflow in the commit message > > Turning page_avail into a unsigned long long is not strictly > needed until we need ability to represent more than 2^32 > 4k pages, which IIUC equates to 16 TB of RAM. That's not > outside the realm of possibility, so makes sense that we > change it to unsigned long long to avoid future problems. > Can you also mention that we're solving this limit too > in the commit message. > > Reviewed-by: Daniel P. Berrangé <berrange@xxxxxxxxxx> Adjusted and pushed. Thank you. Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
