On 2021/1/27 8:06, Mike Kravetz wrote: > On 1/26/21 3:55 AM, Miaohe Lin wrote: >> When subpool max_hpages accounting is not enabled, used_hpages is always 0 >> and might lead to release subpool prematurely because it indicates no pages >> are used now while there might be. > > It might be good to say that you need min_hpages accounting (min_size mount > option) enabled for this issue to occur. Or, perhaps say this is possible > if a hugetlbfs filesystem is created with the min_size option and without > the size option. > > That might better explain the conditions in which a user could see the issue. So commit log might looks like this ? """ If a hugetlbfs filesystem is created with the min_size option and without the size option, used_hpages is always 0 and might lead to release subpool prematurely because it indicates no pages are used now while there might be. In order to fix this issue, we should check used_hpages == 0 iff max_hpages accounting is enabled. As max_hpages accounting should be enabled in most common case, this is not worth a Cc stable. """ If so, should I send a V2 or Andrew would kindly do this? Many thanks. > >> In order to fix this issue, we should check used_hpages == 0 iff max_hpages >> accounting is enabled. As max_hpages accounting should be enabled in most >> common case, this is not worth a Cc stable. > > I agree that such a combination of mount options is very uncommon. > >> >> Signed-off-by: Hongxiang Lou <louhongxiang@xxxxxxxxxx> >> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> >> --- >> mm/hugetlb.c | 16 +++++++++++++--- >> 1 file changed, 13 insertions(+), 3 deletions(-) > > Thanks, > > Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Many thanks for review.
