On Fri, 2012-10-26 at 16:57 +0300, Kirill A. Shutemov wrote: > > > Yes, this code will catch it: > > > > > > /* if an huge pmd materialized from under us just retry later */ > > > if (unlikely(pmd_trans_huge(*pmd))) > > > return 0; > > > > > > If the pmd is under splitting it's still a pmd_trans_huge(). > > > > OK, so then we simply keep taking the same fault until the split is > > complete? Wouldn't it be better to wait for it instead of spin on > > faults? > > IIUC, on next fault we will wait split the page in fallow_page(). What follow_page()?, a regular hardware page-fault will not call follow_page() afaict, we do a down_read(), find_vma() and call handle_mm_fault() -- with a lot of error and corner case checking in between. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href