On Wed, Apr 16, 2014 at 4:42 PM, Kirill A. Shutemov <kir...@shutemov.name> wrote: > On Wed, Apr 16, 2014 at 07:52:29AM +0800, Bob Liu wrote: >> > *ptl = pmd_lock(mm, pmd); >> > - if (pmd_none(*pmd)) >> > + if (!pmd_present(*pmd)) >> > goto unlock; >> >> But I didn't get the idea why pmd_none() was removed? > > !pmd_present(*pmd) is weaker check then pmd_none(*pmd). I mean if > pmd_none(*pmd) is true then pmd_present(*pmd) is always false.
Oh, yes. That's right. BTW, it looks like this bug was introduced by the same reason. https://lkml.org/lkml/2014/4/16/403 -- Regards, --Bob -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
