mm: split folio_pte_batch() into folio_pte_batch() and folio_pte_batch_flags()

Many users (including upcoming ones) don't really need the flags etc, and
can live with the possible overhead of a function call.

So let's provide a basic, non-inlined folio_pte_batch(), to avoid code
bloat while still providing a variant that optimizes out all flag checks
at runtime.  folio_pte_batch_flags() will get inlined into
folio_pte_batch(), optimizing out any conditionals that depend on input
flags.

folio_pte_batch() will behave like folio_pte_batch_flags() when no flags
are specified.  It's okay to add new users of folio_pte_batch_flags(), but
using folio_pte_batch() if applicable is preferred.

So, before this change, folio_pte_batch() was inlined into the C file
optimized by propagating constants within the resulting object file.

With this change, we now also have a folio_pte_batch() that is optimized
by propagating all constants.  But instead of having one instance per
object file, we have a single shared one.

In zap_present_ptes(), where we care about performance, the compiler
already seem to generate a call to a common inlined folio_pte_batch()
variant, shared with fork() code.  So calling the new non-inlined variant
should not make a difference.

While at it, drop the "addr" parameter that is unused.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Suggested-by: Andrew Morton <[email protected]>
Link: https://lore.kernel.org/linux-mm/[email protected]/
Reviewed-by: Oscar Salvador <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Dev Jain <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Gregory Price <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Joshua Hahn <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Mathew Brost <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 1 insertions, 2 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 366e66651c88..4c833b43fef9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1868,8 +1868,7 @@ static inline unsigned int folio_unmap_pte_batch(struct folio *folio,
 	if (pte_unused(pte))
 		return 1;
 
-	return folio_pte_batch(folio, addr, pvmw->pte, pte, max_nr, 0,
-			       NULL, NULL, NULL);
+	return folio_pte_batch(folio, pvmw->pte, pte, max_nr);
 }
 
 /*