On 12/20/19 4:38 PM, Steven Price wrote:
There are a number of minor misuses of the page table APIs in hmm_vma_walk_pud(): If the pud_trans_huge_lock() hasn't been obtained it might be because the PUD is unstable, so we should retry. If it has been obtained then there's no need for a READ_ONCE, and the PUD cannot be pud_none() or !pud_present() so these paths are dead code. Finally in walk_pud_range(), after a call to split_huge_pud() the code should check pud_trans_unstable() rather than pud_none() to decide whether the PUD should be retried. Suggested-by: Thomas Hellström (VMware) <thomas_os@xxxxxxxxxxxx> Signed-off-by: Steven Price <steven.price@xxxxxxx> --- This is based on top of my "Generic page walk and ptdump" series and fixes some pre-existing bugs spotted by Thomas. mm/hmm.c | 16 +++++----------- mm/pagewalk.c | 2 +- 2 files changed, 6 insertions(+), 12 deletions(-)
LGTM. Reviewed-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
