On 04/21/2020 02:33 AM, Will Deacon wrote: > On Fri, Mar 20, 2020 at 10:24:17AM +0530, Anshuman Khandual wrote: >> pmd_present() is expected to test positive after pmdp_mknotpresent() as the >> PMD entry still points to a valid huge page in memory. pmdp_mknotpresent() >> implies that given PMD entry is just invalidated from MMU perspective while >> still holding on to pmd_page() referred valid huge page thus also clearing >> pmd_present() test. This creates the following situation which is counter >> intuitive. >> >> [pmd_present(pmd_mknotpresent(pmd)) = true] >> >> This renames pmd_mknotpresent() as pmd_mknotvalid() reflecting the helper's >> functionality more accurately while changing the above mentioned situation >> as follows. This does not create any functional change. >> >> [pmd_present(pmd_mknotvalid(pmd)) = true] >> >> This is not applicable for platforms that define own pmdp_invalidate() via >> __HAVE_ARCH_PMDP_INVALIDATE. Suggestion for renaming came during a previous >> discussion here. > > Bikeshed alert: maybe pmd_mkinvalid() would be better, given that this is > a one-trick pony for pmdp_invalidate()? I had thought about making it pmd_mkinvalid() earlier. But as we were replacing pmd_mknotpresent(), hence went with similar pattern pmd_mknotvalid() which was originally suggested by Catalin. There is an existing pte_mknotpresent() in arc platform as well. I dont have a very strong opinion either way, will be happy to rename. But then still wondering if we really need to. > > Will >
