On Wed, 2018-09-12 at 11:26 +0100, Will Deacon wrote: > The recently merged API for ensuring break-before-make on page-table > entries when installing huge mappings in the vmalloc/ioremap region is > fairly counter-intuitive, resulting in the arch freeing functions > (e.g. pmd_free_pte_page()) being called even on entries that aren't > present. This resulted in a minor bug in the arm64 implementation, giving > rise to spurious VM_WARN messages. > > This patch moves the pXd_present() checks out into the core code, > refactoring the callsites at the same time so that we avoid the complex > conjunctions when determining whether or not we can put down a huge > mapping. > > Cc: Chintan Pandya <cpandya@xxxxxxxxxxxxxx> > Cc: Toshi Kani <toshi.kani@xxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Yes, this looks nicer. Reviewed-by: Toshi Kani <toshi.kani@xxxxxxx> Thanks, -Toshi
