On 2/3/21 1:08 PM, Peter Xu wrote: > All the regions maintained in hugetlb reserved map is inclusive on "from" but > exclusive on "to". We can break earlier even if rg->from==t because it already > means no possible intersection. > > This does not need a Fixes in all cases because when it happens (rg->from==t) > we'll not break out of the loop while we should, however the next thing we'd do > is still add the last file_region we'd need and quit the loop in the next > round. So this change is not a bugfix (since the old code should still run > okay iiuc), but we'd better still touch it up to make it logically sane. > > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > --- > mm/hugetlb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index d2859c2aecc9..9e6ea96bf33b 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -377,7 +377,7 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t, > /* When we find a region that starts beyond our range, we've > * finished. > */ > - if (rg->from > t) > + if (rg->from >= t) > break; > > /* Add an entry for last_accounted_offset -> rg->from, and > Changing any of this code makes me nervous. However, I agree with your analysis. The change makes the code match the comment WRT the [from, to) nature of regions. Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> -- Mike Kravetz
