On Fri, Jan 22, 2021 at 11:52:27AM -0800, Mike Kravetz wrote: > As hugetlbfs evolved, state information about hugetlb pages was added. > One 'convenient' way of doing this was to use available fields in tail > pages. Over time, it has become difficult to know the meaning or contents > of fields simply by looking at a small bit of code. Sometimes, the > naming is just confusing. For example: The PagePrivate flag indicates > a huge page reservation was consumed and needs to be restored if an error > is encountered and the page is freed before it is instantiated. The > page.private field contains the pointer to a subpool if the page is > associated with one. > > In an effort to make the code more readable, use page.private to contain > hugetlb specific page flags. These flags will have test, set and clear > functions similar to those used for 'normal' page flags. More importantly, > an enum of flag values will be created with names that actually reflect > their purpose. > > In this patch, > - Create infrastructure for hugetlb specific page flag functions > - Move subpool pointer to page[1].private to make way for flags > Create routines with meaningful names to modify subpool field > - Use new HPageRestoreReserve flag instead of PagePrivate > > Conversion of other state information will happen in subsequent patches. > > Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> -- Oscar Salvador SUSE L3
