kthread: simplify kthread_use_mm refcounting

Patch series "shoot lazy tlbs (lazy tlb refcount scalability
improvement)", v7.

This series improves scalability of context switching between user and
kernel threads on large systems with a threaded process spread across a
lot of CPUs.

Discussion of v6 here:
https://lore.kernel.org/linux-mm/[email protected]/


This patch (of 5):

Remove the special case avoiding refcounting when the mm to be used is the
same as the kernel thread's active (lazy tlb) mm.  kthread_use_mm() should
not be such a performance critical path that this matters much.  This
simplifies a later change to lazy tlb mm refcounting.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nicholas Piggin <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions