The main focus of these patches is to improve the performance of binder
page installations, primarily by reducing contention on the mmap_lock.
The idea is to allow concurrent page insertion by leveraging per-vma
locking and folio_walk_start().
Unfortunately, this required reverting the alloc->lock spinlock back
into a mutex in order to serialize with the shrinker. At least until
finding a better solution e.g. support page zapping with a spinlock.
The trade off is still quite worth it though.
Other patches are also included that remove unsafe and redundant things
such as the alloc->vma pointer or the struct binder_lru_page concept.
Note: I'll work on setting up a page fault handler for binder next.
I believe an idea from Alice Ryhl to deferred the page insertions will
make this finally feasible. I only need to figure out a few performance
bits but if/when done most of the manual page insertion code in binder
could be dropped. :)
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Viktor Martensson <vmartensson@google.com>
Carlos Llamas (8):
Revert "binder: switch alloc->mutex to spinlock_t"
binder: concurrent page installation
binder: select correct nid for pages in LRU
binder: remove struct binder_lru_page
binder: use alloc->mapped to save the vma state
binder: remove cached alloc->vma pointer
binder: rename alloc->buffer to vm_start
binder: use per-vma lock in page installation
drivers/android/binder.c | 2 +-
drivers/android/binder_alloc.c | 315 +++++++++++++++---------
drivers/android/binder_alloc.h | 35 +--
drivers/android/binder_alloc_selftest.c | 18 +-
drivers/android/binder_trace.h | 2 +-
5 files changed, 215 insertions(+), 157 deletions(-)
--
2.47.0.199.ga7371fff76-goog